Exploration:
To search through with the view of making discovery. To leave
the beaten track. To investigate and to examine what one might
encounter in regions unknown to humanity or long since
forgotten. Like the eloquent speeches of philosophers, explorers
have always spoken through maps. "Here's the route to the
canyon." "There's where we found the prehistoric
graffiti." "Here's where we took a photo of this
seasonal desert lake facing west."
Yes, maps! What other medium
conveys the proximity of things, directions, distances, vastness
of territories, the reasons why things are what they are, and
even the means to guess where to look for certain things.
These are all types of
geographic information and patterns of geographic data that can
only be documented in map form. It could be said that explorers
merely collect and accumulate geographic information (or rather
geographic "understanding" of certain areas on earth
if we to interpret the word information faithfully) that others
can read and use later to serve their needs. How
laborious--except for the most passionate.
DRY
FACTS
Sounds simple? Well the
Hungarian Count de Almasy (a.k.a. "The English
Patient") once explored the area of Oweinat in the furthest
southwestern part of the Egyptian Sahara along with his British
colleagues. Later, in a great adventure of espionage, he was
able to understand and see the terrain (previously thought to be
unpassable by British patrols) and drew its map in a way that
enabled him to pass through this area with German spies.
Unlike centuries ago when
Europeans always identified it with geography, the concept of
exploration has been extended to cover all sorts of data and
information. Even Microsoft has used the term for its Internet
browser. Interesting when you think about it. It feels like that
when you look at this satellite image (figure 1)--you can see
everything but you don't know what you're looking at! You see
patches of colors, lines and points. You could actually be
looking at the legendary Zarzora Oasis, but you wouldn't know
it. That's when GIS comes to the rescue.
But Zarzora--as well as
the many other Egyptian Sahara historical puzzles, such as the
vanishing Persian army of Cambyses--is still a mystery. This, by
the way, still hasn't had enough effort focused on it from
people fit only to be called Zarzomaniacs! Like them, I feel we
don't have enough resources to explain and explore and at the
same time demonstrate the wonders of GIS.
Instead, I have decided to
focus on a magnificent geographic site at the heart of the known
ancient world's intellectuals. The one location outside Greece
where the works of Greeks and locals reached a zenith that
surpassed the glory of their fellow Greeks. Perhaps because it
was in Egypt.
GEOGRAPHICALLY
WET
In Alexandria, a
sensational discovery shook the archaeological world. In an
underwater site, close to the Qaitbay Citadel on the rocks of
Pharos Island, what seems to some people to be the remains of
the old magnificent lighthouse of Alexandria was found. Nearby
the ruins of a royal sunken palace were identified.
Two thousand years ago,
Queen Cleopatra VII, the last of the Ptolemy dynasty reigned in
Egypt. Although corrupt and declining, the monarchy was deemed
by many as one of the supreme powers of the world. Some of the
greatest events of those almost mythical days must have happened
in this palace. Now, with hundreds and probably thousands of
smaller blocks scattered over the site, there remains little
hope of seeing how things looked in the past, without the use of
a map.
The Centre d'Etude
Alexandrine (CEA), headed by Jean-Yves Empereur, is attempting
to document and understand the history of this civilization
using GIS technology. According to Isabella Hairy, an
archaeologist with CEA, there are more than 200 blocks in the
GIS database (figure 3). What you see as a map on the screen,
the GIS computer holds as a database with lots of descriptive
values called a geodatabase. Each block is drawn in place as a
map feature, and is described in detail in more than 45 fields,
called attributes.
Nelly Martin, chief
surveyor and GIS manager with CEA described the underwater
survey of the location of each block as an adventure. They could
actually measure things found in the murky waters that were hard
to photograph well and also get an overall perception of the
site by referring their locations to the surface. The map
(figure 2) was derived from the geodata of CEA and is, more or
less, all the archaeologists have to depend on to interpret
their archaeologically surveyed material. This geodatabase is
the main source the archaeologists work from to deduce
archaeological facts and physical evidence. Prior to this, most
people only learned about this saga from the words of
Shakespeare.
SHOWTIME!
Let's look at what
information these fortunate archaeologists have at their
disposal. First of all, they have the meticulous work of
collecting the parts that make up the existing geodatabase. This
geodatabase includes the unseen values (attributes such as the
volume, weight, orientation, material type, etc) of each of the
stones. We know GIS acts like any other database system, so
facts such as the tide moving stones of up to four tons, leaving
only larger blocks in place, allows us to answer queries to get
a better picture of things. Yep, it's time to explore! If we
query the GIS for blocks weighing more than four tons, the
result leaves a map with only those blocks whose weight matches
the query's criteria. Now we have a new map that is pared down
to show only those blocks that haven't moved. But, for GIS
analysts, that's not all.
We are reasonably certain
that those blocks must have been part of some architectural
elements such as a pillar, wall, statue and maybe even a sphinx
or an obelisk. Whether it comes from a monolith or other type of
structure, there must be some kind of homogeneity in its
material. It might also be safe to assume that blocks of the
same stone, for instance granite, might lead us to some hidden
relations among the scattered blocks. Consequently, a
hardworking GIS analyst might instruct the GIS--usually very
late at night--to paint the selected large blocks in our newly
drawn map with colors corresponding to their material. In
addition, it might reveal a connection among blocks of the same
stone type that lie within one meter of each other (another of
GIS' wondrous talents). And then, Voila!
ONLY
THE BEGINNING
Of course this is all
hypothetical until actually tested on the blocks' geodatabase
itself (if not already done by the shrewd archaeologists and
GISers of the CEA). However, this one analysis line could prove
impractical if, for instance, all blocks were found to be less
than four tons or if they're all the same good old obliterated
limestone with no exceptions, and lead nowhere. But our above
exercise is only one of the analytical scenarios a skilled GIS
analyst can experiment with to find the truth.
Indeed, the work of
showing geographic information from mere data, whether for
archaeologists or for marketeers, is a job for the most
imaginative analysts. These analysts should forget conventional
database keys and start to think of the geographical keys of
data, which show a more comprehensive picture of our world. If
the coming era's heroes are information analysts, then maybe a
new term could be coined for those who work with GIS. Explorers!
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"Every
map is the sum not only of the cartographer's skills, but of the
many explorers who win the territory in the first place."