One of the more striking artefacts in the Gazetteer from Ptolemy’s Geographia is the curious semicircle of locations in the centre of the Arabian Peninsula.
In effect, Ptolemy developed the first Geographical Information System.
Much more significantly, it makes GIS a natural technology for investigating the catalogue.
In this endeavour we are hugely indebted to the work of the University of Bern who published the entire catalogue of locations from both the Ω and Ξ recensions as a database (Stückelberger & Graßhof 2006).
Unearthing Structure in Ptolemy’s Geographia – Leif Isaksen
6th International Workshop on Digital Approaches in Cartographic Heritage – 2011
Aligning the locations from the Gazetteer with a modern map reveals Ptolemy’s Geographia was updated with [some] locations that align well with the modern Western coastline of the Persian Gulf.
This modern alignment suggests the semicircle of locations is located to the South of Abu Dhabi in the United Arab Emirates.
Also located to the South of Abu Dhabi is a “arch” of 50 villages known as the Liwa Oasis which marks the boundary between the flat coastal desert and the Empty Quarter.
Liwa Oasis is about 100 km south of the Persian Gulf coast and 150 km SSW of the city of Abu Dhabi in the Al Gharbia (Western) Region, on the northern edge of Rub’ al Khali desert.
It is centered around 23°08′N 53°46′E and stretches about 100 km east-west, along an arch curved to the north. It consists of some 50 villages.
A composite image of the semicircle of locations and “arch” suggests the Liwa Oasis marks the rim of a large impact crater that is about 140 kilometres wide.
The alignment of the semicircle of locations towards the Northwest suggests the Liwa Impact Crater is related to the [far smaller] Wabar Craters which align with “incoming objects arriving from the northwest”.
WABAR SITE consists of three craters and a sprinkling of two unusual types of rock – black glass and “impactite.”
The impactite is concentrated on the southeastern rims and is almost entirely absent on the north and west sides of the craters.
This asymmetry suggests that the impact was oblique, with the incoming objects arriving from the northwest at an angle between 22 and 45 degrees from the horizontal.
The Day the Sands Caught Fire
Jeffrey C. Wynn and Eugene M. Shoemaker
Scientific American – Nov 1998
The largest fragment was recovered in a 1966 visit to Wabar and weighs 2.2 tonnes.
The layout of the impact area suggests that the body fell at a shallow angle, and was moving at typical meteorite entry speeds of 40,000 to 60,000 km/h.
Its total mass was more than 3,500 tonnes.
The shallow angle presented the body with more air resistance than it would have encountered at a steeper angle, and it broke up in the air into at least four pieces before impact.
The biggest piece struck with an explosion roughly equivalent to the atom bomb that levelled Hiroshima.
Whether other large impact craters are hidden under the sands of Arabia is a matter of conjecture but the [re-sculptured] Northwest alignment of the Persain Gulf is very striking.
Cenozoic Epeirogeny of the Arabian Peninsula from Drainage Modeling
J W P Wilson, G G Roberts, M J Hoggard, and N J White
AGU Geochemistry, Geophysics, Geosystems 15 – 2014
The origin of the oil in Arabia is also a matter of debate but the location of the Ghawar Field does strongly suggest an abiogenic origin.
Ghawar is an oil field located in Al-Ahsa Governorate, Eastern Province, Saudi Arabia.
Measuring 280 by 30 km (174 by 19 mi), it is by far the largest conventional oil field in the world, and accounts for more than half of the cumulative oil production of Saudi Arabia.
Needless to say, the western [uniformtarian] mainstream geologists cling to their belief that petroleum is a fossil fuel “formed almost exclusively” from “organic material” [aka decomposed dinosaur detritus] and dismiss the abiogenic theory of hydrocarbons.
Whether the Liwa Impact Crater is a primary or secondary impact crater is also a matter of conjecture but the Northwest alignment of the crater does suggest it may be associated with the Canada Basin Impact.
The dating of the Liwa Impact Crater is a matter for informed debate because Ptolemy’s Geographia places the impact [sometime] between 194 BC and 1295 CE whilst the Old Japanese Cedar Tree chronology suggests the impact occurred at the Arabian Horizon in 637 CE.