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\DOI{10.5802/crgeos.273}
\datereceived{2024-02-01}
\daterevised{2024-07-11}
\dateaccepted{2024-09-30}
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\dateposted{2025-04-25}
\begin{document}

\begin{noXML}

\CDRsetmeta{articletype}{research-article}

\TopicFR{Oc\'eanographie, biog\'eosciences oc\'eaniques}
\TopicEN{Oceanography, oceanic biogeoscience}

\shortrunauthors

\title{Alternative crossings into and out of Africa since 30,000 BP}

\alttitle{Autres voies de passage hors d'Afrique depuis 30 000 ans
avant notre \`{e}re}

\author{\firstname{Jerome Eric} \lastname{Dobson}\CDRorcid{0000-0003-4923-6316}\IsCorresp}
\address{Department of Geography, University of Kansas, USA} 
\email[J. E. Dobson]{dobson@ku.edu}

\author{\firstname{Giorgio} \lastname{Spada}\CDRorcid{0000-0001-7615-4709}}
\address{Department of Physics and Astronomy, University of Bologna, Italy} 
\email[G. Spada]{giorgio.spada@gmail.com}

\author{\firstname{Gaia} \lastname{Galassi}\CDRorcid{0000-0002-0533-3889}}
\address{Department of Pure and Applied Sciences, University of Urbino ``Carlo Bo'', Italy} 
\email[G. Galassi]{gaia.galassi@gmail.com}

\keywords{\kwd{Isthmus of Suez}
\kwd{Last glacial maximum}
\kwd{Hypsometry}
\kwd{Sea level change}
\kwd{Isostasy}
\kwd{Ice age}
\kwd{Human migration}}

\altkeywords{\kwd{Isthme de Suez}
\kwd{Dernier maximum glaciaire}
\kwd{Hypsom\'{e}trie}
\kwd{Changement du niveau de la mer}
\kwd{Isostasie}
\kwd{P\'{e}riode glaciaire}
\kwd{Migration humaine}}

%\thanks{}

\begin{abstract} 
Sea levels fluctuated by 125~m over the past 120,000~years,
reaching their lowest during the Last Glacial Maximum (LGM) about
20,000~years ago. Globally an additional 11.6\% of land area was
exposed at LGM compared to today, significantly enhancing migration and
travel opportunities in coastal zones. This study refines the spatial
and temporal precision of ocean levels and coastlines in the Middle
East by retrospectively mapping from 30,000 BP to today using an
improved Glacial Isostatic Adjustment (GIA) model. We explore
alternative land and sea migration routes into and out of Africa including the
Suez crossing between the Red Sea and Mediterranean Sea, the Gulf of
Aqaba route to the Levant, the Bab el Mandab crossing to Saudi Arabia,
the crossing from Foul Bay to the Mediterranean Sea, and the island
route across the Sicily and Messina Straits. The combination of DNA,
archaeological evidence, and retrospective GIA mapping offers a robust
reconstruction of past landscapes, aiding in the understanding of
ancient human migrations and settlements in the region. Our findings
favor south-to-north and east-to-west directions of sequent occupance
in the Nile Valley and highlight ancient Berenice as a key port on Foul
Bay based on archaeological evidence of transportation infrastructure.
The unusual abundance of patch coral formations in Foul Bay raises new
questions about human settlements and demands future exploration.
Investigating Foul Bay's paleogeography and archaeological remains may
provide transformative insights into ancient human mobility and
maritime networks.
\end{abstract}

\begin{altabstract} 
Le niveau de la mer a fluctu\'{e} de 125 m\`{e}tres au cours des 
120 000 derni\`{e}res ann\'{e}es, atteignant son niveau le plus bas lors du
dernier maximum glaciaire (LGM), il y a environ 20 000 ans. \`{A}
l'\'{e}chelle mondiale, 11,6 \% de terres \'{e}merg\'{e}es
suppl\'{e}mentaires ont \'{e}t\'{e} expos\'{e}es lors du dernier
maximum glaciaire par rapport \`{a} aujourd'hui, ce qui a
consid\'{e}rablement augment\'{e} les possibilit\'{e}s de migration et
de d\'{e}placement dans les zones c\^{o}ti\`{e}res. Cette \'{e}tude
affine la pr\'{e}cision spatiale et temporelle du niveau des oc\'{e}ans
et des c\^{o}tes au Moyen-Orient en \'{e}tablissant une cartographie
r\'{e}trospective de 30 000 ans avant notre \`{e}re \`{a} l'aide d'un
mod\`{e}le am\'{e}lior\'{e} d'ajustement isostatique glaciaire (GIA).
Nous explorons d'autres voies de migration terrestres et maritimes
\`{a} partir de l'Afrique, notamment la travers\'{e}e de Suez entre la
mer Rouge et la mer M\'{e}diterran\'{e}e, la route du golfe d'Aqaba
vers le Levant, la travers\'{e}e de Bab el Mandab vers l'Arabie
saoudite, la travers\'{e}e de la baie de Foul vers la mer
M\'{e}diterran\'{e}e et la route des \^{i}les \`{a} travers les
d\'{e}troits de Sicile et de Messine. La combinaison de l'ADN, des
preuves arch\'{e}ologiques et de la cartographie r\'{e}trospective de
la GIA permet une reconstruction solide des paysages pass\'{e}s, ce qui
aide \`{a} comprendre les anciennes migrations humaines et les
\'{e}tablissements dans la r\'{e}gion. Nos r\'{e}sultats favorisent les
directions sud-nord et est-ouest de l'occupation s\'{e}quentielle dans
la vall\'{e}e du Nil et mettent en \'{e}vidence l'ancienne
B\'{e}r\'{e}nice comme un port cl\'{e} de la baie de Foul sur la base
des preuves arch\'{e}ologiques de l'infrastructure de transport.
L'abondance inhabituelle de formations coralliennes en patch dans la
baie de Foul soul\`{e}ve de nouvelles questions sur les
\'{e}tablissements humains et exige des explorations futures.
L'\'{e}tude de la pal\'{e}og\'{e}ographie et des vestiges
arch\'{e}ologiques de la baie de Foul pourrait permettre de mieux
comprendre la mobilit\'{e} humaine et les r\'{e}seaux maritimes de
l'Antiquit\'{e}.
\end{altabstract} 

\maketitle
\vspace*{3pt}
\twocolumngrid

\end{noXML}

\defcitealias{Bosworthetal2019}{ibid.}
\defcitealias{Shaw2003}{ibid.}
\defcitealias{Kotarba-Morley2019}{ibid.}

\section{Introduction}\label{sec1}

{\advance\baselineskip by -.5pt
For three and a half decades, the Out-of-Africa hypothesis has held
that humans originated in Africa and subsequently spread to Europe and
Asia. Inherent in the idea was a high likelihood that the land route
across Lower Egypt and the Isthmus of Suez was an important exit from
Africa to the rest of the world, possibly the main one. Water exit
routes in that region would have included the Nile River, Red Sea, Gulf
of Suez, Gulf of Aqaba, and Bab el Mandab. Now a unified genealogy of
ancient and modern human genomes points to an inferred geographic
center of gravity of the 100 oldest ancestral haplotypes, situated 280
km from the Nile River in Northeast Sudan (due north of Mero\"{e})
(Figure~\ref{fig1}). Inferred human ancestral lineages over time and space
further suggest a narrow, enduring corridor linking that center to the
Levant of Southwest Asia \citep{Wohnsetal2022}.

}

\begin{figure*}
\vspace*{-2pt}
\includegraphics{fig01}
\vspace*{-5pt}
\caption{\label{fig1}(A) Inferred human ancestral lineages over time and space. Each
line represents an ancestor-descent relationship in inferred geneology
of modern and ancient genomes. Line width corresponds to how many times
the relationship is observed, and color intensities are based on the estimated
age of the ancestor. (B) Visualization of the nonparametric estimator of
ancestor geographic location, meaning the average location of the ancestors of
each population from $t = 0$ to ${-}$2,000,000~ya. Widths of lines are
proportional to the number of ancestors of each population over time.
The ancestor is defined as an inferred haplotype with at least one
individual in that population. Source: \citet{Wohnsetal2022}.}
\vspace*{-6pt}
\end{figure*}

{\advance\baselineskip by -.3pt
Yet, pre-dynastic archaeological sites in Egypt are surprisingly rare
for such a crucial corridor lasting 2,000,000~years. A logical
possibility is that physical artifacts were deposited in coastal lands
when sea level was low and subsequently lost to the sea as its level
rose. According to current consensus, the world ocean was at or
slightly above its present level about 120,000~years ago, dropped to
${-}$55~m at 30,000~years ago, fluctuated dramatically in cycles, reached
its lowest level (about ${-}$125~m) at the Last Glacial Maximum (LGM, about 
20,000~years ago), and quickly rose to today's level. The amount of
land exposed and subsequently inundated worldwide is roughly equivalent
to the land area of South America and amounts to an additional 11.6\%
over today's land area. Thus, every human activity that took place in
shallow seas, on beaches, or at varying elevations up to 125~m above
contemporaneous sea level has been inundated. Most artifacts would have
submerged sufficiently in depth and time to undergo substantial subsea
impact.

The first known appearances of early modern humans outside Africa
occurred in Israel by about 194,000 to 177,000~years ago
\citep{Stringer2016} and less certainly in Greece by 210,000~years ago
\citep{Harvartietal2019}. Sites in the Levant of Israel suggest a
waypoint where migration routes from Africa converged for a long
sojourn and then diverged to conquer Eurasia. Similarly, Tunisia and
France appear to be linked through DNA, hinting at a Mediterranean
crossing possibly via Sicily and Messina. Still, no \mbox{exact} routes are
specifically known from the \mbox{Levant}, or Tunisia to France, nor onward to
Europe and Asia. For example, the first known Homo sapiens fossils in
Western Europe were found at Grotte Mandrin in southern France dating
between 56,800 and 51,700~years ago \citep{Slimaketal2022}. Their
Neronian lithic industry found there is ``unknown in any industry of
that age outside Africa''. However, no pathway to Mandrin has been
proven from the Levant nor from Tunisia. These dates correspond to
global sea levels of approximately ${-}$65~m and ${-}$78~m. Immediately
before 56,800~years ago, sea level had risen dramatically from about
${-}$90~m to ${-}$65~m. It topped quickly at the precise date of Grotte
Mandrin and then dropped rapidly so that it reached ${-}$78~m at 
51,700~years ago and ${-}$100 m at 45,000~years ago.

}

\begin{figure*}
\includegraphics{fig02}
\vspace*{-2.3pt}
\caption{\label{fig2}Reference map showing natural features cited,
cities, and known routes connecting the Nile River, Foul Bay, Gulf of
Suez, Red Sea, and Mediterranean Sea throughout history.}
\end{figure*}

{\advance\baselineskip by -.2pt
Experts speak of a Northern Route through the Sinai into the Levant and
a Southern Route across the Bab el Mandab to Arabia (Figure~\ref{fig2}),
but all confirming dates are at least 50,000~years earlier than our
30,000 BP window. Evidence confirming the Northern Route includes:
Early human remains found in the Levant (Skhul and Qafzeh Caves) dated
to 120,000--90,000~years ago and genetic studies of Y chromosome
haplogroups suggesting the Levant as a primary migration path.
\citet{Abbasetal2023} document detailed evidence of intensive travel via
\mbox{pathways} from Wadi Gharandal via Sinai to the Levant. They further
assess climatic conditions at the time and conclude in favor of a
growing consensus for a well-watered Jordan Rift Valley. The main argument 
for the Southern Route is based on mtDNA studies suggesting a broad pattern of
migration via the Horn of Africa. The main argument for Bab el
Mandab is that it fits the ``beachcomber'' hypothesis, which proposes
humans followed coastlines \mbox{eastward,} plus \mbox{archaeological} finds in
southern Arabia dated to 100,000--80,000~years ago. 

}

Here we retrospectively map drowned lands and publish our findings to
help underwater archaeologists optimize their searches for lost
evidence. The exact land routes from Sudan to the Levant are unknown,
but migrants surely would have sought the same factors valued in
historic eras. Thus, preferred routes likely would have traversed
various segments of the Nile Valley, Red Sea, Isthmus of Suez, and Gulf
of Aqaba in one way or another to reach the Levant.


\section{Methods and materials}

We follow \citet{SpadaGalassi2017}, who examined global sea levels from
30,000 BP to today and key intermediate dates. We employ a Glacial
Isostatic Adjustment (GIA) model to account for the Earth's deformation
and gravity variations in response to glacial melting and for a
``gravitationally self-consistent'' reconstruction of paleotopography
\citep{Peltier1994}. This iterative approach allows us to consider
dynamically the role of isostasy in terms of the spatial and temporal
evolution of submerged land and coastlines. In particular, we use
SELEN4 \citep{SpadaMelini2019}, a model that extends the sea-level
equation solver SELEN \citep{SpadaStocchi2007} to any given coastline,
taking into account the horizontal migration of shorelines, the
transition between floating and grounded ice, and the rotational
feedback on sea level \citep{Martinecetal2018}. The computations adopt
the latest version of the ice sheets' chronology progressively
developed by Kurt Lambeck and collaborators at the Australian National
University \citep{LambeckChappell2001,Lambecketal2002,Lambecketal2003}.
The Earth is spherically layered, with a viscosity increase by a factor
of 10 between the upper and lower mantle. In our GIA runs, a uniform
equal-area grid \citep{Tegmark1996} with horizontal spatial resolution
of 20~km is employed; the total integration interval is 30,000~years
with time increments of 500~years.

Data input models and variables include: 
\begin{enumerate}[(a)]
\item Present-day topography constrained by the National Oceanic and
Atmospheric Administration's ETOPO1 global elevation database at 1
arc--minute resolution.
\item Depth-dependence of density and rheological parameters (i.e., a
spherically symmetric Earth model).
\item A set of ``Love numbers'' (measures of spherical viscoelasticity
for the Earth originally conceived by Augustus Edward Hough Love) to a
given maximum harmonic degree (e.g., lmax $=$ 256).
\item A model for the present-day topography (ETOPO1) to define the
present-day ocean function.
\item A raster surface of the Earth on which the sea-level equation is
discretized (global equal-area icosahedron-based spherical grid).
\item Information about the geometry of the ice sheets and about their
time-evolution in the time window of interest (an ``ice model'').
Preliminary analyses employed ETOPO1 global elevation data
\citep{AmanteEakins2009} mapped eustatically by \citet{Dobson2014},
including cartography by Jerry Whistler and a geovisualization by
\citet{Zong2015}.
\end{enumerate}

Other global GIA models exist, e.g., ICE-6G\_C (VM5a) of
\citet{Peltieretal2015}. With respect to the model adopted in this
study, ICE-6G\_C (VM5a) is characterized by different assumptions about
the volume of the major ice sheets at the LGM, the chronology of
de-glaciation, and the viscosity contrast between the upper and lower
mantles. Using SELEN4, we have verified that regarding the evolution of
topography since the LGM, the two models provide consistent scenarios
for the geometry of the choke points. This has been verified even
across the Bering Strait, relatively close to the former Laurentide ice
sheet, where ice distribution and volumes differ significantly in the
two GIA models.

\section{Uncertainty and sensitivity}

Understanding the uncertainties in our data and model results is
crucial for accurately interpreting paleogeographic reconstructions.
This section outlines the key uncertainties affecting our models of the
Red Sea and Mediterranean Sea during the LGM and subsequent periods.

Our GIA model is sensitive to ice history, rheological parameters, and
bathymetry. Key variables influencing the model include the volume and
chronology of ice sheets, Earth's viscosity structure, and sea-level
data. The models rely on ice history reconstructions such as those
developed by \citet{Lambecketal2002} and \citet{Peltieretal2015}.
Differences in these reconstructions, particularly regarding the timing
and extent of ice melt, introduce significant uncertainty. For the Red
Sea and Mediterranean Sea, variations in the volume and timing of ice
melt in far away Arctic and Antarctic realms can alter the predicted
sea levels and shoreline positions.

Accurate bathymetric data are essential for reliable model outputs. We
use the ETOPO1 global \mbox{elevation} database \citep{AmanteEakins2009},
which provides a high-resolution baseline for present-day topography.
However, discrepancies in bathymetric data can lead to errors in
predicted shoreline positions and island formations. The Earth's
viscosity structure, particularly the contrast between the upper and
lower mantle, affects the model's predictions. Our model employs a
spherically layered Earth with a significant viscosity increase between
the upper and lower mantle, which is a standard but simplified
approach. Sea-level proxies used for model calibration vary in
precision and temporal resolution. We have incorporated multiple
proxies to enhance model robustness. Nevertheless, the inherent
uncertainties in these proxies contribute to the overall uncertainty of
our reconstructions.

We verified our model results against alternative GIA models such as
ICE-6G\_C (VM5a) by \citet{Peltieretal2015}. This comparison indicates
that while broad trends are consistent, specific details such as the
timing of shoreline changes sometimes differ. Both models have been
calibrated using numerous sea-level proxies since the LGM, ensuring
that the generated shorelines and island formations are robust across
different scenarios. Our model consistently produces similar results
across multiple runs further attesting to the reliability of our
reconstructions.

Despite these uncertainties, retrospective mapping provides plausible
paleogeographic reconstructions.

\section{Background}

This paper follows four published papers collectively written by
Dobson, Spada, and Galassi. Initially, \citet{Dobson2014} emphasized
the importance of Aquaterra as a global feature.  Aquaterra is the
collective name for all lands that were inundated and exposed
repeatedly during the Late Pleistocene ice ages from the early
appearance of modern humans through today. \citet{SpadaGalassi2017}
refined the boundaries of Aquaterra at course resolution for the whole
world ocean and at fine resolution for certain regions. They produced
GIA reconstructions to account for the earth's deformation and
horizontal migrations of shorelines in response to glacial melting.
Dobson, Spada, Galassi (\citelink{Dobsonetal2020}{2020})
produced GIA {reconstructions} for nine
global chokepoints---Bering Strait, Isthmus of Panama, Bosporus and
Dardanelles, Strait of \mbox{Gibraltar,} Straits of Sicily and Messina,
Isthmus of Suez, Bab el Mandab, Strait of Hormuz, and Strait of
Malacca---to determine the status of each at the LGM, 20,000~years ago.
Seven of the nine global chokepoints were dramatically impacted, and
four of them---Bering Strait, Bosporus and Dardanelles, Strait of
Hormuz, and Strait of Malacca---did not exist as navigable waterways.
We conducted an in-depth analysis of the Bering Strait, noting
especially the Bering Transitory Archipelago which was digitally
discovered by us and would have been a stepping-stone pathway from
Siberia to Alaska (Dobson, Spada, Galassi, \citelink{Dobsonetal2021}{2021}).

The most complex changes affecting distance and direction occurred at
the Isthmus of Suez, thereby establishing the regional prominence of
Foul Bay, Egypt (Figure~\ref{fig2}). To minimize overland travel, a
better alternative was Foul Bay to the Nile River at Syene (Aswan),
Antinopolos, or Coptos, thence down the Nile River to the Mediterranean
Coast. In particular, closure of the Gulf of Suez due to low sea level
at LGM favored a dramatic shift in travel routes linking the Red Sea
and Mediterranean Sea (Dobson, Spada, Galassi, 
\citelink{Dobsonetal2020}{2020}). If Berenike
Troglodytica, a settlement on Foul Bay, existed at that time, it would
have been the main beneficiary of any modicum of economic and
population growth that occurred. We propose naming the hypothesized,
now inundated, ancient port city Berenice Aquaterra.

Dobson, Spada, Galassi (\citelink{Dobsonetal2020}{ibid.})
surveyed literature on ancient trade, transport,
watercraft, potential cargoes, and durable structures such as stone
buildings. We found sufficient evidence to suggest that boats and
maritime travel, transport, and trade existed in a few locations around
the world well before LGM, Australia about 65,000~years ago being the
most cited case \citep{Clarksonetal2017}. Pottery and other likely
cargoes were available. The oldest known stone structures date from
11,000 BP while Foul Bay retained most of its land. Hence, ports
potentially spawned by increased trade in Foul Bay may still be
detectable based on stone artifacts. 

Here we study the push and pull factors that might have driven major
changes in transportation and migration routes at LGM and afterward. We
examine evidence of human occupance in Foul Bay. Our findings should be
of interest to {underwater} {archaeologists}, anthropologists, historians,
geographers, Egyptologists, and others interested in human settlements
and migrations over the past 30,000~years.\looseness=-1

Global choke points consist of two distinct geomorphologic types:
straits which channel traffic through concentrated sea lanes or
isthmuses which require overland crossings and favor short distances
with unimpeded terrain. Straits facilitate maritime transport as does
the open sea, while isthmuses inhibit maritime transport compared to
open sea. The only isthmuses recognized as choke points are narrow and
strategically positioned ones that consequently offer relatively less
resistance and facilitate maritime shipments arriving from each side
and departing from the other. The Suez crossing is an isthmus reached
by open sea on the north and a long, narrow gulf on the south, but for
the past century and a half it has functioned as a pseudo strait due to
the Suez Canal. Foul Bay is neither a strait nor an isthmus, but it
could have functioned as a pseudo isthmus due to its relatively
advantageous overland crossing to the Nile River.

The Suez Canal is a global choke point channeling cargo between the
Mediterranean Sea and Red Sea and thus today connecting the vast
Mediterranean Sea/Atlantic Ocean and Black Sea realm with the vaster Red
Sea/Indian Ocean/Pacific Ocean realm. In previous research, we and others 
demonstrated that at the LGM, the Gulf of Suez was exposed land, thus
making the Isthmus of Suez a land barrier 520~km wide (north--south) 
(Dobson, Spada, Galassi, \citelink{Dobsonetal2020}{2020}).
In this new research, we explore alternative
crossings from Foul Bay (Sinus Immundus) on the western Red Sea Coast
to the Nile River, thence downriver to the Nile Delta and into the
Mediterranean Sea (Figure~\ref{fig2}).

At LGM the route crossing directly between the Mediterranean Sea and
Red Sea was a daunting portage (Figures~\ref{fig3} and~\ref{fig4}). The
Gulf of Suez remained dry land with little improvement in overland
travel until after 14,000~BP. By 13,500~BP, lakes appeared, but they
did not constitute a continuous waterway until about 13,000~BP. The
gulf reached its full length in 8000~BP, and the shore of the
Mediterranean Sea retreated by 7000~BP. From 30,000~BP, when our
timeline begins, until 10,500~BP there was no Foul Bay. Indeed, the old
coastline contained not even a natural harbor until about 
16,000 BP. Approximately 80~km
south of Ras Banas, the coast gently curved in a concave fashion but
offered little shelter. The first reasonable harbor later formed 20~km
south of the tip of Ras Banas and remained physically intact for the
next 9000~years, reaching the dimensions envisioned by Strabo. Then
suddenly, the rising sea reached the shallow base of Foul Bay's floor,
and the embayment filled rapidly, reaching its shape of today about
7000~BP.\looseness=-1

\begin{figure*}
\includegraphics{fig03}
\vspace*{-5pt}
\caption{\label{fig3}Inundation of Gulf of Suez from 20,000 to
6500~BP.}
\vspace*{-3pt}
\end{figure*}

\begin{figure*}
{\vspace*{-2pt}}
\includegraphics{fig04}
{\vspace*{-2pt}}
\caption{\label{fig4}Inundation of Foul Bay from 20,000 to 6500~BP.}
\end{figure*}

{\vspace*{-1pt}}

\section{Animated comparison of changing transport advantage}

{\vspace*{-1pt}}

To understand what sea level change did to transportation routes in
Egypt spanning 30,000~years, readers must visualize change in three
dimensions over time for two or more different locations. To facilitate
such geovisualization, we offer both animations in the same frame,
synchronized so that one timeline controls both simultaneously
(Figure~\ref{fig5} and Supplementary Materials).  Go to Supplementary
Materials and click on the file name: 
suez-foulbay\_geovisualization.mp4. When the two
images form, you can control the animation from its timeline. Using the
cursor and timeline at the bottom of the
animated figure, readers can watch from beginning to end, stop action
at any time to study in detail, or run continuously for any part of the
whole. We ourselves began by watching 30,000~years of change over and
over. Only in this way does one fully grasp the ``synchronized
swimming'' of coastal lands over ages. Then we repeatedly stopped and
started purposefully at 500-year increments. Only in this way can one
compare what specific actions are occurring at Foul Bay versus the
Isthmus of Suez. 

\begin{figure*}
{\vspace*{-2pt}}
\includegraphics{fig05}
\caption{\label{fig5}Synchronized videos of Foul Bay and the Isthmus of
Suez over 30,000~years of sea level fall to LGM and subsequent rise to
today. (Reader, please see Supplementary Material to activate animation.)}
{\vspace*{-2pt}}
\end{figure*}

{\vspace*{-1pt}}

\section{Berenice Troglodytica}

{\vspace*{-1pt}}

In ancient times, three cities in quite different locations were named
Berenice (or Berenike). Berenice Troglodytica (or Trogodytai without an
``l'' in one case, probably an error) was on Foul Bay but not
coincident with today's Berenice. In 46 ancient maps
(\citeauthor{Kamal1926}, \citelink{Kamal1926}{1926, 1928, 1932, 1933} 
and Supplementary Materials) the
descriptive adjective Troglodytica appears 12 times, 4 of them attached
to the city name and 8 as a region or district surrounding the town.
Two other towns had the same root name Berenice. Berenice Epidire was
south of the Bay of Aseb (Assab), which lies near the southern tip of
Eritrea. Berenice Pancrisia (Panchrysos ``all gold'') was a major
center for gold mining and smelting generally thought to be somewhere
inland, perhaps in Wawat, which was famous in ancient times but lost
for centuries. Today, most sources place Berenice Pancrisia in Wadi
Allaqi, Sudan, less than 4 miles from the Egyptian border and 70 miles
inland (southwest of Foul Bay). These three cities appear to have been
distinct, and their repetitive names are not considered to be
indicative of uncertainty among cartographers. One map shows Berenice
Pancrisia erroneously placed where Berenice Epidire should be, and that
appears to be an unrelated error. To add to the confusion, there are
three other Foul Bays in the world: one on Tiran Island at the northern
end of the Red Sea, one on Barbados, and one in Australia. 

Berenice Troglodytica on Foul Bay was a major port 2000~years ago. The
standard account is that it became a port in 275 BCE and was named by
Ptolemy~II Philadelphus for his mother Berenice I of Egypt. It was
prominent for a while as a transshipment point for elephants heading
first from India and later from present Eritrea to Lower Egypt for
military deployment against the Seleucids. 

Geographers from Strabo to Ellen Churchill Semple cited goods from
India following the inland route from Berenice. ``Hence under Greek and
Roman rule in Egypt the Oriental products continued to move overland
from Leucos Limen (Quseer, Myos Hormos) or Berenice to Coptos on
the Nile, and thence by river down to Alexandria, whence they were
exported to all coasts of the Mediterranean.'' \citep[p. 169]{Semple1939}
And enormous sums changed hands, ``Aside from the costly carriage by
donkey or camel caravan from the Red Sea, traffic charges by this
{marine} and river route were heavy: they included transit \mbox{duties} on all
goods entering and leaving Egypt, and customs \textit{ad valorem}
imposed at the frontier of the various nomes or provinces, where custom
houses were maintained or a bridge of boats blocked\break the passage.''

The archaeological evidence from Berenice includes remnants of harbors,
warehouses, and other infrastructure that supported commerce at least
as far away as India. Discoveries through 2012 included early Roman
ship timbers, large ropes, thin fragments of lead (some with nail
holes), a \mbox{cattle} \mbox{cemetery} \citep{SidebothamZych2012}, and a pet
cemetery \citep{Tarlach2021,Osypinskaetal2021}. Team members
attempted with partial success to delineate harbor walls. A geophysical
survey of the site was completed in 2014 \citep{Zychetal2016}. Zych and
Sidebotham (\textit{Archaeology Magazine}, 
\citelink{ArchaeologyMagazine2014}{2014}) and
\citet{Sidebothametal2015} unearthed part of a ship's hull while
studying a Hellenistic fort, Roman harbor, and Late Roman temple and
conducting other fieldwork.

A recent summary reveals revolutionary new understandings of Berenice
\citep{Marchant2024}. The site itself is described in vivid detail with
startling ties to India, not merely in trade goods but in cultural and
business ties with India. The first Buddha statue ever found west of
Afghanistan was discovered in this ``once-bustling, cosmopolitan port
city from which mighty ships laden with gold and wine sailed across the
ocean and brought back spices, jewels, perfume and other exotic 
cargo\,\ldots~driving a broad reassessment of the interconnectedness of the
ancient world\,\ldots. One Greco--Roman text, known as the
\textit{Periplus Maris Erythraei}\,\ldots\ lists the port as a hub for
maritime trade routes stretching south as far as modern-day Tanzania,
and east, past Arabia, to India and beyond\,\ldots\ by the first century
A.D., the Roman tax revenues from Indian Ocean trade may have generated
as much as one-third of the {[}Roman{]} empire's total income\,\ldots\ 
[or] perhaps at 10 or 15 percent lower\,\ldots'' Site archaeologist
Steven Sidebotham and team have ``uncovered mounds of administrative
detritus, including letters, receipts and customs passes, and imported
treasures such as ivory, incense, textiles, gems and foodstuffs such as
pots of Indian peppercorns, coconuts and rice.'' He hopes ``beyond''
will prove to be China, but no evidence of that has been found. We urge
investigators to explore new horizons in time as well as space, while
we ourselves search for Berenice Aquaterra.

According to \citet{Wozniak2021}, ``Abraq (discovered in 1832) was a
large Hellenistic fort located in the mountains southwest of Berenike.
A survey by the Berenike Project in the 1990s traced an overland trail
connecting the fort to Syene \citep[pp.~41--42, 128]{Sidebotham2011}. The
eastern part of the route could have led to Berenike, according to the
researchers, although this would have been a rather roundabout way,
Abraq being too far south. A much shorter and equally convenient 
route\,\ldots~from Berenike to Syene would have led through via Wadi Abu
Greiya, for example. \mbox{Assuming} a certain similarity of the trail in
question to the well-known routes from Berenike or Nechesia to Edfu and
Koptos, its final destination on the coast (a port?) would have been
southeast of the Abraq fort, that is, south of the present port of
Shalateen\,\ldots~it could have been an ``alternative'' or ``rescue''
route\,\ldots''. 

Berenice Troglodytica was active as an east--west connection between the
Red Sea and the Nile River in the 1st and 2nd Centuries CE and again in
the 4th Century CE, noted by geographers Strabo (64 or 
63~BCE--24~CE), Pliny the Elder (23--79~CE), and Stephanus of Byzantium (6th
Century CE). A road ran directly westward to the First Cataract of the
Nile River at Syene (now Aswan), closely following the Tropic of
Cancer. After 137~CE the Via Hadriana ran from Berenice to Antinopolos
(Antino\"{o}polis, Antinoopolis, Antino\"{e}) for trade heading upriver
into Nubia. A third road ran from Berenice to Koptos during the Roman
era. The port was abandoned after the 6th Century CE, and all three
roads fell into disuse. Berenice itself disappeared until 1818 when
ruins were identified by Giovanni Battista Belzoni~(1778--1823),
confirming an earlier opinion by Jean Baptiste Bourguignon d'Anville
(1697--1782).

\section{Berenice today}

Berenice, Egypt is a small port town located at the northernmost end of
Foul Bay and sheltered from the Red Sea by Ras (Head) Banas. Google
Earth and other modern sources still label it Berenice Troglodytica,
but many maps simply say Berenice, Baranis, or Berenike. Foul Bay
itself extends about 150~km north-south and 20 to 45~km east--west. It
served as a port of call for the U.S. Sixth Fleet in the early months
of the Persian Gulf War (1990--1991). The town contains a small Bedouin
Museum, a few unmarked structures, and a major archaeological site, the
so-called Temple of Serapis. The temple reputedly was built by Trajan
(53--117~CE), but archaeologists from the Polish Center for
Mediterranean Archaeology discovered in it a pair of reliefs, one
dating from 2134--1690 BCE and the other 1674--1549~BCE, far older than
Trajan or the town itself (\textit{Archaeology Magazine}, 
\citelink{ArchaeologyMagazine2014}{2014}). 

Archaeological excavations have been underway continuously since the
mid-1990s, notably by Sidebotham (University of Delaware), 
Zych and R\k{a}dkowska (University of Warsaw), Wo\'{z}niak
(Polish Academy of Sciences), and  Wendrich (University of
California at Los Angeles and Leiden University). Funders have included
the Netherlands Foundation for Scientific Research, National Geographic
Society, Netherlands Ministry of Foreign Affairs, Samuel H. Kress
Foundation, University of Delaware, UTOPA Foundation, and American
Philosophical Society.

\section{Tectonic forces and movements}

The only competing force capable of negating the hypsometric impacts of
changing sea level would be vertical tectonics, which are not included
in our GIA adjustments. Certainly, there has been substantial movement
in the past because Foul Bay and the Gulf of Suez lie on active plate
boundaries \citep{Bosworthetal2019}. Here, however, we are concerned
only with a specific time period---30,000 BP to about 8000 BP---direction
offsetting the impact of sea level change by rising when sea
level was falling (30,000 BP to LGM) or falling when sea level was
rising (LGM to 6500 BP), and only three relatively small areas---Foul
Bay, the Gulf of Suez, and the Isthmus of Suez where the Suez Canal now
lies. Despite its proximity to the Red Sea Rift, Foul Bay shows no
evidence of measurable tectonic activity in the relevant period.
Focusing on Zabargad (St.\ John) Island, which lies on the plate
boundary 40~km east of Foul Bay and El Ikhwa (Northern Brother) Island,
which is also on the plate boundary 275~km north of Foul Bay, 
\citet{HoangTaviani1991} concluded that both islands had been ``tectonically
quite stable'' for 125,000 years. Likewise, maps presented by
\citet{Bosworthetal2019} show no recent tectonic activity in or near\break
Foul Bay.

The Gulf of Suez has been more active. According to 
\citetalias{Bosworthetal2019} ``All of the margins of the\ \ldots\,Gulf of
Suez\,\ldots\ underwent tectonically-driven rift shoulder uplift and
denudation in past, particularly during the main phases of continental
rifting. \mbox{However,} during the past 125~ka uplift has been much more
focused and most pronounced at the footwalls of a few, active
extensional faults. These include a few major faults in the Gulf of
Suez \ldots'' The most prominent of these faults are Gebel Tanka and
Gebel Zeit-Shadwan Island, both of which are oriented parallel to the
Gulf of Suez route and therefore would not have impeded water flow nor
human transport even if all of their vertical movement had occurred
during the relevant time period.

\section{Other hypothesized crossings}

{%\advance\baselineskip by .3pt
It is essential to consider all land and water routes that may have
facilitated human migration in and out of Africa when sea level was
high or low. Here we mention three potential crossings: (a) the Gulf of
Aqaba, (b) the Bab el Mandab, and (c) the Straits of Sicily and
Messina. 

\smallskip\noindent
\textbf{Gulf of Aqaba:} When our research began, we were interested
primarily in traffic between the Red Sea and Mediterranean Sea. As the
work progressed, our focus shifted to include the Levant. For
consistency, it would have been good to have the same retrospective GIA
mapping for the Gulf of Aqaba as for the rest of the region.
Fortunately, Aqaba is so different from Suez that GIA precision is
unnecessary. It is so deep throughout its length, and its shores are so
steep that (a) it would have been navigable end to end even at LGM, (b)
its width changed little, (c) the lengths of routes were little
affected, and (d) tectonic activity would not have blocked transport
\citep{Sadeetal2009,HamoudaEl-Gharabawy2019}. Thus, it was open and may
well have been an important route from the eastern shores of the Red
Sea toward the Levant.

\smallskip\noindent
\textbf{Bab el Mandab:} Reconstructions of the southern Red Sea by
\citet{Inglisetal2019} provide valuable insights. Studies by 
\citet{Baileyetal2019} 
emphasize the Bab el Mandab's role in facilitating movement
from Africa to the Arabian Peninsula. Many sources say that narrowing
of the Bab el Mandab would have made it a viable crossing. However, our
retrospective GIA mapping finds that its east--west width was never less
than 3~km even at LGM (Dobson, Spada, Galassi, 
\citelink{Dobsonetal2020}{2020}). This narrowing would
have made it a dangerous crossing for small craft. Significantly, 
\citet{Wohnsetal2022}
 show extremely weak DNA linkages to nodes east of
Bal al Mandab, compared to strong linkages across the Isthmus of Suez.
Together the incomplete closure and weak DNA connection lead us to
deemphasize Bab el Mandab in our study.

\smallskip\noindent
\textbf{Straits of Sicily and Messina:} At LGM the Mediterranean Sea
was almost two separate seas divided by the Island of Sicily, the
closed Strait of Messina, and the narrowed Strait of Sicily. Still, the
water crossing was 52~km wide and at least 80 m deep 
(Dobson, Spada, Galassi, \citelink{Dobsonetal2020}{2020}).
There is reason to suspect that the first modern humans in France
crossed via these islands, based on a prominent inferred geographic
center of ancestral haplotypes in northwest Africa and scattered ones
across in Mediterranean Europe.\looseness=-1
}

\section{Origins of Egyptian cultures}

What difference might an alternative pathway (that is, Foul Bay to Nile
Delta versus the Suez crossing) have made in the prehistoric settling
of Egypt and subsequent development of Egyptian cultures? We
hypothesize that the Suez crossing alone, whenever advantageous, would
have favored settling the Nile Valley from north to south. The crossing
itself is at the northern extreme, and anyone heading southward from
the Mediterranean Sea could have chosen to navigate directly up the
Nile River. Conversely, anyone heading northward from the Red Sea could
have veered westward to the Nile Delta on a route so level and
unimpeded that for a while it served as Necho's Canal \citep{Lloyd1977}. Logically, the
Suez crossing would have contributed little to development in southern
Egypt, except that some travelers might have rejected that route
because of its length and intervening coral hazards and crossed instead
from Myos Hormos to Coptos in Upper Egypt, which at 150~km is the
shortest of all crossings between the Red Sea and Nile River. Assessing
Greco-Roman ports on the Red Sea, \citet{Kotarba-Morley2019} states,
``\ldots\ beyond brief references in classical texts\,\ldots'' 
Regarding the western Red Sea Coast  \citet{Wozniak2021} says,
``\ldots~Myos Hormos (Quseir al-Qadim), Nechesia (Marsa Nakari) and
Berenike have been located and surveyed\,\ldots~and, in the south,
Ptolemais Theron (Nowarat delta in Sudan) and Adulis (Galala in
Eritrea). Notably, these sites are located at regular distances, every
\mbox{150--200~km.} Locations were \mbox{chosen} either at existing sites or, for the
most part, in places without earlier settlement\,\ldots~The only region
where such centers were not recorded is the section between Berenike
and Ptolemais Theron.'' Both Kotarba-Morley and  Wo\'{z}niak list
Adulis, which is located in Eritrea near the Bab el Mandab, too far
south to have influenced settlement\break in Egypt.

A true test of the north to south settling hypothesis would focus on
the LGM and associated millennia when sea level was low enough to
influence collective travel habits. We ourselves confidently model
isostatic sea level for the past 30,000~years but not earlier due to
ice data limitations. Based on this constraint and sea level curves, we
select a time {window} of 30,000 to 6500~BP. Hominin
occupance\footnote{The word ``occupance'' has a long tradition of use
in settlement geography. While ``occupy'' or ``occupancy'' can be
momentary, ``occupance'' implies a long term act of settling.
``Sequent occupance'' implies a succession of occupants over seasons,
years, centuries, or millennia.
(\url{https://www.merriam-webster.com/dictionary/occupance}).} lasting
hundreds of thousands of years has been documented in the Nile River
Valley and more broadly in Northeast Africa, the Sahara Desert, Sudan,
the Levant, and so forth. The evidence starts with Homo erectus and
continues to modern human predynastic cultures that are clearly
Egyptian \citep{Shaw2003}. Ideally, the test should include
unassailable demographic data for the entire Nile Valley, Foul Bay,
Isthmus of Suez, and neighboring regions. However, archaeological data
from excavations covering the relevant years are quite sparce.\looseness=-1

Traditionally, scholars have divided the Nile River Valley into Lower
Egypt, which includes the entire Nile Delta plus about 100~km of the
river valley upstream from Cairo to Beni Suef (29\textdegree N, near
Giza) and Upper Egypt which extends from Beni Suef to the First
Cataract of the Nile (24\textdegree N) at Syene (Aswan). Many sources,
starting in the 19th Century, further divide Upper Egypt into Middle
Egypt from Beni Suef to Sohaq (26\textdegree 33$'$N) versus the
remaining Upper Egypt from Sohaq to Aswan. Accordingly, for this study,
we define Lower Egypt from 31\textdegree 35$'$N to 29\textdegree N,
Middle Egypt from 29\textdegree N to 26\textdegree 33$'$N, and Upper
Egypt from 26\textdegree 33$'$N to 24\textdegree N.

Egyptian culture derives from two distinct cultural hearths,
Al-Bad\={a}r\={i} (4400--4000 BCE) \citepalias{Shaw2003} and Naqada
(4400--3000~BCE) \citep{PetrieQuibell1895, Shaw2003,Deeetal2013}. 
Both existed in \mbox{predynastic} Egypt beside the Nile
River. Al-Bad\={a}r\={i} lies in Middle Egypt halfway (335~km straight
line distance) upriver from Giza and 325~km downriver from the First
Cataract of the Nile. Naqada lies near Coptos, thoroughly in Upper
Egypt about three-fourths of the way (500~km) upriver from Giza and
150~km downriver from the First Cataract. 

Where, in turn, did the forerunners of these predynastic cultures
reside before migrating to their known sites? A litany of studies,
complementary or contradictory, suggest a ``melting pot'' of diverse
origins for Al-Bad\={a}r\={i} \citep{Shaw2003}, which itself may date
as early as 7000~BP \citep{Watterson1998}. Shaw cites and \mbox{rejects} an
early Tasian culture with precursors in Lower Egypt and Neolithic
Sudan, but he does allow for a nomadic Sudanese influence on Badari
culture. He further cites likely origins in the Sahara Desert and
possibly the Levant. Side-blow flakes are characteristic of Badari and
certain cultures in the Sahara. Characteristically Badarian artifacts
have been uncovered well beyond Al-Bad\={a}r\={i} as far as
Hierakonpolis (100~km from Aswan), suggesting that the culture may have
extended far into Upper Egypt. \citet{Shaw2003} says, ``Relations with
the Red Sea are attested through the presence of Red Sea shells in
graves, while copper ore may have come from the Eastern Desert or the
Sinai\,\ldots~If there were contacts between the Badari region and the
Sinai, they most probably passed through the Eastern Sinai rather than
Lower Egypt.'' In this case, the most likely ports into and through the
Eastern Desert would be either Myos Hormos or Berenice to Coptos.

Naqada's origins have been heavily debated. Here we revisit existing
literature in search of indicators that may point toward one migration
pathway or another. Hypothetically, if Naqada was settled primarily
from Nubia (south) or, alternatively, from the Sahara (west) or Levant
(east) or Europe (north), what would that say about sea to sea
crossings? Settlers arriving via Foul Bay could go directly into the
Upper Nile but so might settlers from Wadi Halfa and the rest of
riverine Nubia. Settlers from the Sahara might go directly to Upper
Egypt but also to Middle or Lower Egypt. Migrants arriving from Europe
or the Levant might cross the Isthmus of Suez but traveling east to
west, rather than crossing north to south, and then continuing
southward upriver. Once in the Nile Valley, they might settle anywhere
from the Nile Delta southward to Aswan. 

\begin{figure*}
{\vspace*{2pt}}
\includegraphics{fig06}
{\vspace*{2pt}}
\caption{\label{fig6}Distributions of biological affinities described
in \protect\citet{Braceetal1993,Haniharaetal2003,Keitaetal1996,
Godde2009,Godde2018,KeitaBoyce1996,ProwseLovell1996,
Lovell1999,ChriscoGodde2022,Ehret2023}. 
All affinities represented here apply to
predynastic Naqada except those otherwise noted on the map.}
\end{figure*}

The consensus gleaned from current research shows a melting pot of
diverse cultures sharing biological traits in many directions
(Figure~\ref{fig6}). Close biological affinities link Naqada with its
neighbors in the Nile Valley including Al-Bad\={a}r\={i} some 175~km
upstream, and that is true for thousands of years with predecessors,
contemporaries, and descendants. The next greatest affinities are with
Mesolithic Nubia. Lower Egypt forms a homogeneous group, which is part
of an overall gradient from least Naqada affinities in the north to
greatest in the south \citep{Godde2018}. Conversely, Naqada's weakest
affinities are with ancient Europe, the Levant, the Tropics, and
certain stretches of the Nile Valley itself.

Among nine archeological sites in the Nile Valley at least 5000~years
old, none are in Lower Egypt, one is in Middle Egypt, five are in Upper
Egypt and three are in Nubia (Table~\ref{tab1}). Hence, the actual
pattern of early settlements favors settling northward from Nubia or
westward from Foul Bay or Myos Hormos to the Nile River and downriver.
The timing of both sites at 6400~BP, however, comes late in the
inundation of Foul Bay, when almost all of its water had returned, and
any influence on settlement would have been inertial at best.

\begin{table*}
\caption{\label{tab1}Archaeological sites in the Nile River Valley at
least 5000~years old}
\begin{tabular}{cccccc}
\thead
Site name &amp;Age &amp; \parbox[t]{3cm}{\centering Location (common language)}  &amp; Longitude &amp;Latitude &amp; Major division\vspace*{2pt} \\
\endthead
Jebel Sahaba   &amp; 15,000--13,000  BP &amp; Near Wadi Halfa, Sudan &amp; 31\textdegree24$'$E  &amp; 22\textdegree30$'$N &amp; Nubia        \\
Nabta Playa    &amp; 11,000--8000 BP   &amp; Western Desert, Egypt  &amp; 29\textdegree12$'$E  &amp; 22\textdegree18$'$N &amp; Nubia        \\
Bir Kiseiba    &amp; 15,000--12,000 BP  &amp; Near Abu Simbel, Egypt &amp; 23\textdegree52$'$E  &amp; 22\textdegree31$'$N &amp; Nubia        \\
Wadi Kubbaniya &amp; 14,000--12,000 BP  &amp; Near Asyut,  Egypt     &amp;32\textdegree48$'$E   &amp; 25\textdegree54$'$N &amp; Upper Egypt  \\
Nazlet Khater 4&amp; 14,200--11,100 BP  &amp; Near Sohag, Egypt      &amp; 31\textdegree09$'$E  &amp; 27\textdegree15$'$N &amp; Middle Egypt \\
Taramsa Hill   &amp; 6200--5200 BP    &amp; Near Qena, Egypt       &amp; 32\textdegree50$'$E  &amp; 25\textdegree48$'$N &amp; Upper Egypt  \\
Naqada         &amp; 5800--5000 BP    &amp; Near Luxor, Egypt      &amp; 32\textdegree46$'$E  &amp; 25\textdegree58$'$N &amp; Upper Egypt   \\
Hierakonpolis  &amp; 5000--4000 BP    &amp; Near Edfu, Egypt       &amp; 32\textdegree43$'$E  &amp; 24\textdegree53$'$N &amp; Upper Egypt  \\
Badari         &amp; 5000--4000 BP    &amp; Near Asyut, Egypt      &amp; 31\textdegree27$'$E  &amp; 26\textdegree08$'$N &amp; Upper Egypt  
\botline
\end{tabular}
\end{table*}

\section{Uncertainty regarding Berenice's location}

Here we note that diverse locations are given for Berenice Troglodytica
on ancient maps, and we ask why.

\begin{figure*}
{\vspace*{-3pt}}
\includegraphics{fig07}
{\vspace*{-3pt}}
\caption{\label{fig7}``Berenice according to the opinion of some
Geographers.'' Source: Long, G. ed. J. Mickleburgh, ``Ancient Egypt.''
Maps of the Society for the Diffusion of Useful Knowledge, London,
1844.}
{\vspace*{-3pt}}
\end{figure*}

The American Geographical Society Library (AGSL) in Milwaukee, WI,
holds a 16-volume Atlas, the~\textit{Monumenta Cartographica Africae et
Aegypti} edited by~\citeauthor{Kamal1926}
(\citelink{Kamal1926}{1926--1952}) which was given to
the Society by editor Kamal, a prince of Egypt. It contains copies of
the oldest known maps of the Red Sea and Africa, and only a few copies
exist in the world.  Dobson studied one copy at the Egyptian
Geographical Society in 1999 and another at AGSL in 2018. He examined
46 ancient maps of the Red Sea containing the basin now occupied by
Foul Bay (\citeauthor{Kamal1926},  
\citelink{Kamal1926}{1926, 1928, 1932, 1933}; See Table~S1 in Supplementary Material). 
Taking photographs and extensive notes, he
analyzed Foul Bay and especially the location of Berenice. He found
that there was indeed much confusion among ancient cartographers about
the location of Berenice. Of 43 maps that show Berenice, 17 place it at
the northern end of Foul Bay, 19 in the middle, and three at the
southern end. Three maps even point to one site at the northern end
plus an alternative site in the middle with a cartographer's note
saying, ``Berenice according to the opinion of some Geographers''
(Figure~\ref{fig7}). The other two doubtfully say ``Position
attr\`{i}bu\'{e}e \`{a} Berenice.'' The confusion is pervasive and also
clearly stated as scholarly uncertainty by three separate teams of
cartographers. The earliest known maps of the Red Sea Coast do not
resolve Berenice's location even in early historic times, much less in
prehistory.

No one knows how many people lived in the exposed land subsequently
inundated by the rising Red Sea. There is no evidence to suggest a
dense population, but neither is there evidence to exclude it. There is
no evidence to suggest a settlement with a port function, but neither
is there evidence to exclude it. Hence, in fairness, we consider
Scenario A with few people and no port versus Scenario B with many
\mbox{people} and a port settlement capable of handling cargo and trading
inland and\break seaward.

In Scenario A, a scattered, low-density population simply would have
dispersed to nearby lands as sea level rose. The influence on
subsequent population and settlement patterns in lands surrounding Foul
Bay would have been minimal.

In Scenario B, however, total population likely would have declined
substantially as (a) land, roads, and buildings were lost to rising
water and (b) the city's port function diminished as traffic shifted
back to the rapidly improving Suez route. Vestiges of the old city
would have migrated upward contour by contour, retaining any high
ground that continued to be viable near shore. With this inundation
process in mind, we suspect that population dispersal would have
occurred outward in all directions from Foul Bay and along the
east--west route from Foul Bay to the Nile River. If a port city existed
and especially if it were sizable enough to occupy much of the basin,
its footprint ($x,y$) would have migrated erratically depending on
hypsometric ($z$) patterns. Its precise location might well have
confounded 19th Century cartographers and other scholars who were
unaware that inundation had occurred below. Thus, the \mbox{uncertainty} about
the location of Berenice observed in ancient maps and in diverse
opinions much later favors Scenario B over Scenario A.

Why such uncertainty? The logic of Scenario B suggests that a city may
have developed on the \mbox{exposed} floor of Foul Bay's basin as sea level
fell to ${-}$125~m and remained low for several thousand years. We suggest
naming the hypothetical city Berenice Aquaterra to avoid confusion with
the three known Berenices. We envision a theoretical scenario in which
a settlement occupying substantial portions of Foul Bay was gradually
inundated as shown in Figure~\ref{fig4}, based on time slices within a
30,000-year \mbox{reconstruction.} Due to steep slopes at lower depths, Foul
Bay's horizontal extent of inundation was insignificant until about
16,000~BP. Losses of coastal lands were noticeable by 14,000~BP and
substantial by 10,500~BP. Most of the basin was inundated by 9000~BP,
but scattered remnants of its bottom remained as late as 7000~BP.
Inundation was complete by 6500~BP.

\section{Searching for ancient stone artifacts in Foul Bay}

It is generally accepted that no stone pyramids existed before the
earliest one visible above sea level today; that is Djoser's Pyramid
from 2670 BCE. Yet, Foul Bay remained dry for as long as 5000~years
after the first stone construction is known to have \mbox{occurred} on land 
i.e.\ G\"{o}bekli Tepe in 11,500 to 10,000~BP \citep{KinzelClare2020}.
Elsewhere on dry land, however, terrestrial stone artifacts such as
monuments, stelae, and statues have been dated as early as the
Neolithic \citep{Schmidt2007}. Recently at Flying Foam Passage in
Western Australia, five ancient stone artifacts were found at ${-}$11 to
${-}$14~m in association with a submerged freshwater spring at
archaeological site WH1 in Murujuga (Dampier Archipelago) and dated to
the Early Holocene or Late Pleistocene \citep{Benjaminetal2023}. It is
likely that some stone structures exist in some shallow seas somewhere.

The earliest fired clay object of any kind, i.e.\ the
Venus of Doln\'{i} V\v{e}stonice at 26,000~BP, was much earlier
\citep{Vandiveretal1989}.

Foul Bay is quite shallow over much of its extent. Almost all its floor
was still exposed as recently as 9500~BP. Inundation was rapid from
9000 to 7000~BP. At least
half of its land was still \mbox{available} for \mbox{occupance} as late as 9000
years ago, and the rest continued to be available in diminishing
quantities for another 2500~years. Thus, it would not change the
global timeline of stone structures if, in the deeper portions of Foul
Bay, archeologists were to find stone structures coincident with the
construction of G\"{o}bekli Tepe. The same cannot be said for pyramids
per se, since even the shallowest portions or Foul Bay were inundated
2000~years before Djoser's Pyramid was built. It would not change the
timeline of pottery if fired clay objects were found anywhere in Foul
Bay. It would change the timeline and raise major questions about the
settlement of Egypt if stone structures or fired clay objects were
found at or below ${-}$25~m where coastlines remained steady for 105,000
continuous years.\looseness=-1

It is unwise to take for granted the absence of anything beneath the
ocean surface simply because it has not been seen and recorded. For
example, a substantial part of the Lighthouse of Alexandria was missing
for more than 500~years in spite of its well-trafficked location,
widespread knowledge of precisely where it had stood, and great public
interest in finding it again. When blocks of granite, statuary,
obelisks, and columns amounting to more than 70 tons of material were
rediscovered in 1994, they were lying prone at a depth of 2--9~m beside
the base where it was known to have stood \citep{AbdelazizMohamed2019}.
\looseness=-1

\begin{figure*}
\vspace*{-2pt}
\includegraphics{fig08}
\vspace*{-3pt}
\caption{\label{fig8}Simulated scenario of a Sudanese pyramid changing
over time on dry land versus submerged conditions.}
\vspace*{-3pt}
\end{figure*}

\section{Patch coral reefs}

The challenge will be finding archeological evidence to support or deny settlement,
and the overwhelming object and obstacle of that search will be coral reefs.
Foul Bay lies in the global zone where reefs dominate shallow oceans
wherever hard substrates exist in clear water with low-energy currents.
Here is a notional drawing of how a Sudanese pyramid might look today
on land versus underwater \mbox{(Figure~\ref{fig8}).} Of course, excavation
will be impeded severely by the usual constraints of underwater
archeology and, more so, by the need to preserve corals with or without 
suspicion of precious artifacts inside.

Coral reefs in and around Foul Bay can provide insights into past sea
level changes and environmental conditions. Corals are sensitive to
changes in water depth, temperature, and salinity, making them
\mbox{excellent} indicators of past marine conditions. Uranium-series dating
of corals has been used to \mbox{reconstruct} sea levels and provide timelines
recording when certain areas were submerged or exposed. Studies by
\citet{HoangTaviani1991} on coral reefs from uplifted Red Sea islands
offer crucial data for validating GIA models and understanding the
timing of sea level changes in the region.

Coral reefs must be anchored to a solid substrate such as natural
stone, stone masonry, brick, concrete, or previously established coral
reef itself. Patch corals, also called platform corals, exist in
shallow waters wherever bare substrate provides an anchor, hydrologic
and climatic factors support growth to the surface, and sandy bottom
surrounds and constrains each reef to its own column. We posit that, if
a settlement were to be inundated in Foul Bay, its most likely form
would be scattered patch corals, rising from a maximum depth of 125 m
to the surface. 

In 1998, Dobson proposed that some of the world's patch coral reefs in
shallow tropical seas might overlie stone structures. He purchased a
full set of nautical charts for all of the world's oceans and seas and
searched diligently for patch coral reefs in depths of ${&lt;}$125~m
throughout the latitudinal zone of coral reefs worldwide. Searching the
entire World Ocean, he found that Foul Bay conspicuously stood out as
the largest concentration of patch coral reefs on earth. His research
notes record his very first impression of Foul Bay, ``Rocks all over.
Some regular geometric patterns in 30 to 64~m of water. Dense.
Impressive. No doubt why sailors dubbed it ``foul'' for shipping. Some
formations are straight or slightly curving lines like buildings spaced
along a boulevard. Most run parallel to the coast. Most clusters could
have been physical or cultural. Long fringing reefs that seem natural
are scattered about, interspersed in shallow water. A total count of
306 patch coral reefs.'' (Figure~\ref{fig9}). See Table~S2 in
Supplemental Material.

\begin{figure*}
\includegraphics{fig09}
\caption{\label{fig9}Patch Coral Reefs and Sea Floor Depths in Foul
Bay, Egypt. Soundings in meters. (This chart is NOT VALID FOR
NAVIGATION, and we have removed all coordinate information so readers
will not be tempted to use it that way.) Cartographic Data Source: National Oceanic and
Atmospheric Administration, International Hydrographic Charts, Chart
\#62230, \citep{NOAA2013}. Cartographic legend is explained in Chart \#1 
\citep{NOAANGA2019}. Red dots represent rocks which cover and uncover or are awash
at low water. Blue dots represent rocks at uncertain depth which are
hazardous to navigation even though always covered.}
\end{figure*}

Conditions on the Egyptian Red Sea Coast are ideal for corals 
\citep{Berumenetal2019}. Journalists speak in glowing terms of ``the last coral
refuge'' and its ``super-corals.'' At any given depth, that
favorability depends on latitude, wave energy, and turbidity underlain
by sufficient solid substrate to anchor reefs. The upward growth of
patch coral reefs is measured in terms of vertical accretion of
carbonate skeletons from Scleractinia, also called ``hard corals'' and
``stony corals.'' \citet{Dulloetal1996} 
\mbox{measured} \mbox{vertical} accretion at
several depths and sites of Porites colonies in fringing reefs near the
Marine Science Station at Aqaba. The rate was 0.67~m/kyr for the last 
5~kyr. \citet{Braithwaite1982} studied reefs in the North Towartit and
Shambaya Groups of the Sudanese Red Sea.\looseness=-1 
%\vspace*{-4pt}


\section{Berenice Aquaterra; crossroads of antiquity?}


Retrospective GIA mapping reveals striking possibilities of altered
crossings between the Red Sea and Mediterranean Sea. Foul Bay attains a
competitive advantage when sea level is low and loses that advantage to
the Gulf of Suez when sea level is high. What cannot be ascertained is
the level of demand at LGM. Common knowledge and scholarly opinion
assume that demand was near zero, but that is an assumption based on
terrestrial archaeology. No systematic archaeological survey has been
conducted for the now submerged lands that would have been the
foundation of coastal commerce at that time. We stipulate that humans
were present in the vicinity but do not speculate regarding the number
of people residing in subsequently inundated settlements or actively
crossing sea to sea in such ancient times. Rather, we advocate a
program of exploration and research to determine how many people
resided in the region and in Foul Bay when it was dry. Only when that
approximation is known with reasonable certainty will it be possible to
determine whether Berenice Aquaterra was a few scattered homes, a
village, or a major port. 

Hypothetically, if the sea levels of 14,000~BP or earlier were to occur
\textit{today} when populations are sizable and mobile, Berenice
Aquaterra undoubtedly would become a major port, surpassing cities on
the Suez Canal itself since far larger port functions---docking,
unloading at one end, transshipment, and loading at the other
end---would be necessary for overland crossing. In 2021, the Suez Canal
carried a record 1.27 billion tons of cargo on 20,694 vessels and
earned \dollar6.3 billion in transit fees. Imagine what the economic impact
would be if that cargo and finance passed through two Egyptian cities,
Berenice and Aswan, overland between them, and up and down the Nile
River. The number of employed {longshoremen}, alone, would be enormous,
not to mention myriad other trades and professions. \mbox{Transportation}
infrastructures stretching 300~km from end to end would be built and
maintained over multiple routes. Egypt might dominate world transport
and possibly world trade.

The keys to Berenice Troglogytica's success as a settlement and port
2000~years ago depended on two primary factors: its natural, strategic
appeal to commercial interests and a demand for port services due to
local, regional, and global trade. Likewise, if population and trade
had been great enough ten or twenty thousand years earlier, Berenice
likely would have been the crossroads of antiquity. Whatever
maritime traffic existed between the Red Sea and Mediterranean Sea
would have relied heavily on that route. With an overland portage at
its back, Foul Bay would have required break-of-bulk that, combined
with its unique location, might have encouraged a settlement and
perhaps a\break nascent port. 

With sufficient traffic, Berenice Aquaterra could have been an
entrep\^{o}t, possibly a uniquely important one, in contrast to its
relative insignificance today. In geographic terminology, an
entrep\^{o}t is a principal transshipment location---city, port, or
trading post---where goods are imported and exported, stored, and
traded. From ancient to modern times, the largest urban settlements on
earth have been entrep\^{o}ts that are ``break-of-bulk'' points where
bulk cargo arrives from overseas and must be divided into smaller loads
for transport inland or to smaller settlements on nearby coasts or
islands. In the opposite direction, cargo arrives in small loads from
the interior and must be aggregated into larger bulk shipments for
sailing to foreign ports. New York, London, Sydney, Tokyo, Istanbul,
and Cairo are prime\break examples.

By about 6500~BP sea level had shifted so that the Gulf of Suez route
was more efficient in those same measures, and after 1869 CE the Suez
Canal eclipsed all other routes. As for demand, Berenice Troglodytica
experienced heavy use of its port facilities from 275 BCE to the 6th
Century CE including centuries when Berenice Troglodytica was a key
stop for goods transported between Egypt and India. By 500 CE demand
shifted back to Suez so that Berenice Troglodytica's port effectively
went out of business, and the town itself was lost. By that time, Foul
Bay was cluttered with patch corals, then as now an obstacle to
navigation.


\citet{Kotarba-Morley2019} proposed parameters of attractiveness
designed to compute quantitative scores for site suitability based on
sea, land, resources, and socio-economic/political variables.
Fortunately for our study, she chose Berenice Troglodytica as her
prototype. Her computational model fits within the broad category of
screening methods for land use suitability, which can be local,
regional, or global in coverage. Screening techniques such as this
experienced a huge boost in capability and popularity when geographic
information systems (GIS) emerged in the 1970s. Indeed, the first
article using GIS in research mode ever to appear in a mainstream
geographic journal demonstrated a regional screening procedure for land
use suitability analysis. Its {application} was to select candidate areas
for large electrical generating facilities in the U.S. State of
Maryland  \citep{Dobson1979}.

\citet{Kotarba-Morley2019} is the leading expert on ancient ports in
and around the Red Sea. Her screening algorithm takes the perspective
of hypothetical motivators who recognize the need for new ports and
proactively seek suitable sites. For the most part, all sites are
treated as possessing inherent characteristics that may or may not be
of interest to hypothetical developers. Sites passively wait for
developers who may or may not appear. In reality, it is more likely
that the earliest development at each place began with a single boat
sailing into safe harbor, mooring for a short while, and exchanging
goods with local residents; the port function then grew with repetition
boat by boat, shipper by shipper, and buyer by buyer. Foresight and
pro-active assessment would have begun when governments and businesses
recognized strategic needs and decided to invest. At that point, port
facilities would be added to the matrix and would influence
attractiveness along with natural features.

{\advance\baselineskip by -.2pt

In summary, \citetalias{Kotarba-Morley2019} algorithm judged the Berenice
Troglodytica of 275 BCE to 500 CE to be ``a practical and a rather
attractive location,'' rating 2.6 out of 4 (0.65) on all combined
measures. Its sea features were ``moderately attractive'' at 0.72 and
its socio-political-economic features were ``moderately attractive'' to
``very attractive'' at 0.85. ``Berenice is naturally strategically
located on top of an uplifted promontory with good all-round views,
including the entire Foul Bay and the entrance to a number of
surrounding wadis, and this position would have enabled the sending of
signals to forts and stations located in the foothills of the
\mbox{mountains.} A score of 4 is achieved\,\ldots\ not only due to its
defensive position and viewshed location, but also because it
benefitted from good connections with the hinterland via a number of
caravan routes supported by well-positioned and well-defendable
stations, forts and praesidia
\citep{Bagnalletal2001,SidebothamZitterkopf1995}.'' On one measure
alone, demand, did Berenice rate a perfect score. Demand initially
under the Ptolemies was driven by the need for African elephants and
later under the Romans by concern for efficient transshipment of Indian
Ocean goods.

How would these scores have changed over the past 30,000~years?
Prevailing scholarly opinion today would suggest little demand before
275 BCE and after 500 CE. It is crucial, however, to avoid falling into
self-fulfilling projections. If substantial trade existed at LGM, the
demand for a port in Foul Bay would have been greater than at any other
time in the past 30,000~years, due to its strategic position
potentially connecting the Atlantic Ocean/Mediterranean Sea realm with
the Red Sea/Indian Ocean/Pacific Ocean realm. If substantial trade
existed, Berenice could have been an entrep\^{o}t like no other. 

Consider, also, that Kotarba-Morley's glowing assessment of Berenice's
strategic position evoked a period when sea level was almost as high as
today. For many thousands of years before, during, and after LGM, low
sea level would have reshaped land and water so that Berenice's
overview would have been more strategically advantageous than today, as
would its access to the interior. We respectfully suggest that it would
be helpful to add one more parameter of attractiveness dedicated to
scoring global and regional access from a strategic standpoint. 

Procedurally, we hope Kotarba-Morley will share her extensive database
of ancient Red Sea ports in a geographic information system (GIS). As
\citet{Sinclairetal2019} say, ``In\,\ldots~thirty years and 
more\,\ldots~archaeological  field surveys have been transformed by the
availability of satellite imagery, GPS location and GIS mapping to
investigate relationships between finds and landscape features.''
Beyond mapping per se, GIS emerged as an essential analytical
capability for understanding all types of distributions, movements, and
flows in precisely the ways that parameters of attractiveness require.
What we would like to see most is attractiveness scores for Foul Bay
and the Isthmus of Suez compared through 30,000~years of sea level
change under a range of population scenarios.

}

\section{Discussion}

The implications of sea level change over the past 30,000~years are
potentially transformative for archaeologists, anthropologists,
evolutionary biologists, historians, geographers, Egyptologists, and
other scholars. We asked, for example, how modern humans got from their
original home in Africa to their eventual homes in Europe and Asia? 
\citet{Baileyetal2019} state,  ``Supporting field evidence for or against
[a certain] hypothesis of an early coastal dispersal is almost
non-existent, arguably because the relevant areas and time periods in
question are now submerged below modern sea level.'' Are crucial
pathways and meeting points now submerged and therefore difficult to
investigate? What difference might alternative pathways have made in
the prehistoric settling of Egypt and subsequent development of
Egyptian cultures? Assessing Greco-Roman ports on the Red Sea,
\citet{Kotarba-Morley2019} states, ``\ldots\ beyond brief references in
classical texts\,\ldots\ Aside from Myos Hormos, Adulis, and Berenike, no
other exact and unequivocally confirmed location of an actual harbour
within a Classical port town is known.'' Did some of those missing
ports exist earlier than presently known so that key evidence is now
submerged?\looseness=-1

We describe and analyze alternative crossings at prehistoric dates with
confidence because their physical geographies are based on rigorously
measured elevation and bathymetry data and mapped hypsometrically
according to retrospective sea level projections that account for
global isostasy and are well established in scientific literature. It
would be hard to argue against the diminutions of Foul Bay and the
Gulf of Suez at the LGM and reappearance later because they are evidence-based and
straightforward. However, such dramatic changes in travel distances and
directions necessarily imply equally striking possibilities in human
geography, archaeology, anthropology, and history, which are far more
debatable. We urge all disciplines to consider the impacts of sea level
change when studying ancient Egypt. To that end, we make our results
available to all in Supplementary \mbox{Materials}.

We contend with confidence that displacements of human migratory routes
by ${&gt;}$700~km horizontally and ${&gt;}$125~m vertically, as found here, would
cause transformative changes in human geography. We~\mbox{offer} the profusion
of patch corals in Foul Bay and the uncertainty of Berenice
Troglogytica's location as mysteries that may shed light on the human
geography of Berenice Aquaterra.

Is there any remaining evidence of material culture under Foul Bay? We
searched for and found no archeological record of submerged stone
structures. However, we discovered that patch corals are
extraordinarily abundant in Foul Bay, noted that corals require a solid
substrate, and now recommend systematic exploration to determine
whether its substrates are natural or constructed.

How reliable is the current understanding of Berenice Troglodytica's
age and location? We discovered and documented a long record of
cartographic confusion regarding its precise location on Foul Bay. We
posited that such extreme uncertainty favors our Scenario B in which a
coastal settlement developed at the LGM and migrated
laterally while rising upward. Its precise location over time might
well have confounded 19th Century cartographers and other scholars who
were unaware of the inundation that had occurred below.

Do current understandings of predynastic Egyptian culture and
biological affinities match low-sea-level or high-sea-level pathway
configurations? We found that (a) settling first in Upper Egypt and
then Middle Egypt and (b) biological affinities among Naqada and
al-Bad\={a}r\={i} and neighboring regions, near and far, favor a
low-sea-level pathway configuration.\looseness=1

We also asked if predynastic and prehistoric populations were large
enough to create ports and other transportation hubs, but no answers
were found in scholarly literature for locations submerged today.
Indeed, we found no comprehensive attempts to study the matter.

Following these leads must necessarily question established theory and
conventional wisdom regarding ancient Egyptian migration, human
settlement, and cultural development, and will, no doubt, generate
controversy. It is important to keep in mind that the only audacious
aspects of our scenarios are the simultaneous, complementary behaviors
of the two waterbodies (Foul Bay and Gulf of Suez), and those interpreted behaviors are firmly
founded in standard theory. The true \mbox{uncertainties} are population
densities and mobilities at such ancient times, in which case we state
our scenarios as hypothetical and caution future researchers against
assuming values too high or too low.

The existence of Berenice Aquaterra can be tested only by
reconstructing palaeolandscapes and conducting archaeological surveys.
Resurgence in this type of research around the world (Europe, North
America, Arabia, Australia, and South Africa) makes such vertically
integrated investigations a realistic prospect  \citep{Baileyetal2017}.
\citet{Mclarenetal2020} advocate a stepwise process: (1) create
localized sea level curves, (2) generate detailed bare earth digital
elevation models, (3) create \mbox{archaeological} predictive models, (4)
verify the models using archaeological prospection, and (5) demonstrate
that archaeological materials found date to the late 
Pleistocene. We advocate urgent application of this
five-step process to the Suez and Foul Bay crossings.

\section{Conclusions}

This study constitutes a strategic reassessment of changes in sea level
and associated pathways in and out of Africa since 30,000~BP. We
retrospectively map sea level fluctuations and their effects on coastal
landscapes in the Middle East, especially in terms of likely migration
routes. Using an improved Glacial Isostatic Adjustment (GIA) model, we
refine the spatial and temporal precision of ocean levels and
coastlines from 30,000~BP to the present. We acknowledge uncertainties
in the GIA model, particularly regarding ice history reconstructions,
earth's viscosity structure, and bathymetric data. These factors can
influence predicted sea levels and shoreline positions, highlighting
the need for continued refinement of models and data sources.

Global sea levels fluctuated by 125~m over the past 120,000~years.
They reached their lowest level during the LGM
about 20,000~years ago, thereby exposing an additional 11.6\% of land
area globally and significantly enhancing migration and travel
opportunities in coastal zones. The research examines the Suez crossing
and Foul Bay\textbackslash Nile River\textbackslash Mediterranean Sea
crossing and considers the Gulf of Aqaba route to the Levant, Bab el
Mandab crossing to Saudi Arabia, and Straits of Sicily and Messina. Key
findings include: 
\begin{itemize}
\item Berenice Aquaterra is hypothesized as a crucial port on Foul Bay,
based on geographic principles of regional development and \mbox{analogous}
archaeology of 2000-year-old Berenice Troglodytica and its
transportation infrastructure.
\item An unusual profusion of patch coral formations in Foul Bay raises
new questions about potential human settlements and warrants further
exploration.
\item Uncertainty in cartographic representation of Berenice
Troglodytica's location fits a proposed inundation scenario well
enough to encourage exploration of Foul Bay and the patch coral
formations in it.
\item The study indicates south-to-north and east-to-west directions of
sequent occupance in the Nile Valley, challenging conventional wisdom
about ancient Egyptian migration patterns.
\end{itemize}
{\advance\baselineskip by -.1pt
The methodology integrates DNA evidence, archaeological literature, and
retrospective GIA mapping to reconstruct past landscapes, providing
insights into ancient human migrations and settlements. This
multidisciplinary approach offers a robust framework for understanding
human geography, especially historical mobility and maritime networks.
The authors emphasize the importance of investigating Foul Bay's
paleogeography and underwater archaeological remains, suggesting that
such research could provide transformative insights. 

This study demonstrates the significant impact of sea level changes on
human migration patterns and coastal settlements during the late
Pleistocene and early Holocene. It underscores the value of integrating
geophysical modeling with archaeological and genetic evidence to
enhance collective understanding of human prehistory. The findings open
new avenues for exploration and research, particularly in submerged
coastal areas, and enhance existing narratives about human migrations
out of Africa.

}

\section*{Declaration of interests}
The authors do not work for, advise, own shares in, or receive funds
from any organization that could benefit from this article, and have
declared no affiliations other than their research organizations.

\section*{Acknowledgments}
We sincerely thank Donald W. Jones, Adjunct Professor, Department of
Classics, University of Tennessee, Knoxville; Martin J. Pasqualetti,
Arizona State University; Geoff N. Bailey, University of York; and
James A. Harrell, University of Toledo (retired) for reviewing
early drafts of our manuscript and offering solid advice. Harrell was
especially helpful in apprising us of literature and findings at the
Berenike excavation site. Bailey did the same for many major Red Sea
sites. Extensive conversations with Bailey and Harrell explored the
sensitive interface between archeology and our disciplines. We deeply
appreciate the cordial and professional manner in which Fran\c{c}ois
Chabaux, co-editor-in-chief of \textit{Comptes Rendus Geoscience}, and
three anonymous reviewers evaluated our research and improved it
tremendously with their expert knowledge of the diverse topics
necessarily involved in age-old mysteries of place, time, and human
behavior. Figures showing the results of our GIA model have been drawn
using the Generic Mapping Tools (GMT) of \citet{WesselSmith1998}. The
Sea-Level Equation solver can be downloaded
from:~\url{https://gmd.copernicus.org/articles/12/5055/2019/gmd-12-5055-2019.html}. 
GS is funded by an RFO grant of DIFA. We deeply appreciate
the dedicated assistance of Marcy Bidney and her staff at the American
Geographical Society Library in Milwaukee, Wisconsin and the
exceptional efforts of Greg March (University of Tennessee Map Library)
to provide the nautical chart behind Figure~\ref{fig9}. Jeffrey R.
Dobson, Robert B. Honea, and Robert G. Lipscomb are appreciated for
their abiding input to the conception and vetting of the ideas
presented in this paper.

\back{}

\section*{Supplementary data}
Supporting information for this article is available on the journal's
website under \printDOI\ or from the author.  

\CDRsupplementaryTwotypes{supplementary-material}{\cdrattach{crgeos-273-suppl1.pdf}}
\CDRsupplementaryTwotypes{supplementary-material}{\cdrattach{crgeos-273-suppl2.pdf}}
\CDRsupplementaryTwotypes[video/mp4]{supplementary-material}{\cdrattach{suez-foulbay-geovisualization\_h264.mp4}}

\nocite{Dobsonetal2020,Dobsonetal2021,ArchaeologyMagazine2014}

\printbibliography
\refinput{crgeos20240074-reference.tex}

\end{document}
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