|Proof of Theory - 1.09 Mercator’s submarine islands off Brazil and in the Caribbean|
Page 10 of 11Mercator’s 1569 map shows several submerged or semi-submerged plateaus and islands off the eastern coast of Brazil and in the Caribbean (Figure 1.62a). The islands marked F and G represent Vila Dos Remédios and St Helena, respectively, and island I appears to be a small islet that is presently barely visible above sea level. Critically, though, are the island groups A and H, which seem to represent a plateau that is partially flooded, with scattered islets visible above sea level. There are corresponding submarine plateaus on the actual ocean floor, suggesting that Mercator had source maps or map descriptions from a time when the sea level was low enough for these plateaus to be partially exposed. Islands B to E likewise have corresponding submarine ‘islands’, which could (arguably) only have been visible above sea level many thousands of years ago. It must be pointed out that one of the two islands in group E is presently visible above water (see Figure 1.62a inset and Figure 1.62b enlargements). Islands B to D are not visible on the NASA shallow topography map and are probably well below see level. The MS Encarta Interactive World Encyclopedia map however appears to be somewhat in error, as it places practically all of island group E below 50 fathoms, whereas both islands are actually visible from the sky (NASA shallow topography). The bathymetry maps Island J on the Mercator map seems to correspond to the plateau marked J on the MS Encarta and NASA bathymetry maps. What would have possessed Mercator to draw these islands (B to D, at least) in the locations he chose, unless he had sources describing its presence in those very locations?
Figure 1.62a. Submarine plateaus and islands on Mercator’s 1569 map and probable locations on the corresponding ocean floor maps [MS Encarta Interactive World Atlas, NASA], download a HIRES image here.
Figure 1.62b. NASA images of Brazilian islands and submarine plateaus, NASA Shallow Bathymetry (top), NASA Bathymetry (centre) and enlargements (bottom), download a HIRES image here.
As intriguing as the coastal map of Brazil is Mercator’s rendition of the islands of the Caribbean (Figure 1.63a, top). The NASA topography map of the corresponding area (Figure 1.63a, bottom) shows what is at present above sea level. Prominent landmarks like Cuba, the Dominican Republic and Puerto Rico are easily recognizable and were not numbered.
The numbered islands on Mercator’s map can be readily identified on the Encarta map of the Caribbean, as shown in Figure 1.63b (top). Islands a,b,c and d appear much larger on the Mercator map, the relative sizes corresponding with the high-lying submarine areas as marked on the Encarta map. The most intriguing aspect of the Mercator map is once more the two semi-submerged plateaus marked h, l and m. Why would Mercator have chosen to draw multiple islets in exactly those locations, unless he had sources indicating as much? Of particular interest also is the island group numbered j (blue dots), which corresponds to the mostly submarine plateau as indicated on the Encarta map. The islands marked n, o, p and q also seem to have matching underwater locations. Can all of this be nothing but coincidence? The NASA bathymetry maps of Figure 1.63b (bottom) depicts the Caribbean ocean floor, but identification of the islands under discussion is more difficult because of the particular depth scale used.
Figure 1.63a Maps of the Caribbean, Mercator (top), NASA Topography (bottom), download a HIRES image here.
Figure 1.63b Maps of the Caribbean, Encarta IWA (top), NASA bathymetry (bottom), download a HIRES image here.
In order to determine which time period Mercator’s mythical islands date back to, one would require a finer indexed depth scale for the NASA and Encarta maps. It should be stressed, however, that a sea level of only 10m below present would date back to about 8000 years ago (Figure 3a of my Enigmas chapter).
FEEDBACK RECEIVED FROM FORUMS AND EXPERT OCEANOGRAPHERS
I am indebted to a forum member who pointed out that the 'islands' on the submerged plateaus in the Caribbean may actually represent a warning of shallow waters to sailors at the time of Mercator. This prompted me to page through my map books in search of clarification and I was not disappointed. The 1625 map of the Caribbean by Henry Briggs shows shallow waters demarcated by dashed lines as well as islets within these areas (Figure 1.64, centre). This proves that some of these islands must have been above sea level at the time when the maps were drawn, either by Middle Age cartographers or their earlier equivalents. Obtaining topography maps with high resolution elevation data of the shallow water regions proved to be rather difficult (selected areas at NGDC, possibly available at BODC), but I nevertheless received valuable feedback from a couple of experts in the field who generously replied to my enquiries.
Figure 1.64 Maps of the Caribbean, Mercator 1569 (top), Briggs 1625 (centre), Modern (MS Encarta IWA, bottom), download a HIRES image here.
It is apparently well known amongst oceanographers who have studied the Caribbean that several of the islands in this area have been washed away by hurricanes, even as recently as the late 1800s. A good example of this phenomenon is the Dry Tortugas group of islands, clearly marked as such on the Briggs map (E), of which several islands had disappeared by 1875.
Based on this evidence I have to conclude that the mapping of the Caribbean most likely had very little to do with maps dating from thousands of years before and that the information must indeed have been obtained by the early Portuguese and Spanish explorers. The same cannot be said of the Brazilian islands, though, unless the disappearance of islands B to D and the second island of group E can be attributed to some (other) kind of natural phenomenon.