Biggest-ever river delta plain found
University of Bergen scientists identify ancient geographical feature in the Arctic
M. Michael Brady
In April, University of Bergen scientists reported finding the world’s biggest-ever river delta plain. It’s not one of today’s world, but one that topographic features of the Barents Sea region between the north of Norway and the northwest of Russia clearly show existed in the Triassic Period before the beginning of the Jurassic Period more than 200 million years ago. Named the Triassic Boreal Ocean (TBO) delta plain, it was enormous. Were it to exist today, it would be 10 times the area of the Ganges Delta, now the world’s largest, and its area on the face of the globe would be larger than that of the State of Alaska.
As often happens in research and science, the finding of TBO was not the outcome of a dedicated search for it but of an unforeseen result of another quest. In a search for viable fossil fuel finds on the Norwegian continental shelf, geologist Tore Grane Klausen and colleagues examined core samples drilled by energy exploitation and production companies and reviewed seismic data. In the plethora of data acquired, the pattern of a Triassic Period river delta plain emerged in what now is the Barents Sea. The observation of a bit of it at Hoppen in Svalbard archipelago confirmed the find.
The Triassic Period was one of large sizes. There was one supersized land mass, Pangaea. Dinosaurs, a family of animals that included the largest land species of all time, roamed it. The largest-ever delta, the TBO, was formed. Since then, Pangaea rifted and broke up into the continents as we now know them. In the Cretaceous-Paleogene extinction event of about 66 million years ago, three-quarters of the plant and animal species on Earth perished.
The TBO delta was most likely formed by sediments from mountain chains created in the formation of Pangaea. The drainage for it might have been twice as large as that which feeds the Mississippi River. From the vantage point of today, the scientific find of the TBO suggests that there still are new ways of studying the Earth’s distant past.
“Har funnet historiens største deltaslette i Barentshavet” (Have found largest ever delta plane in the Barents Sea) by Tore Grane Klausen, Aftenposten, April 30, 2019: www.aftenposten.no/viten/i/kJv9nj/Har-funnet-historiens-storste-deltaslette-i-Barentshavet (in Norwegian).
“The largest delta plain in Earth’s history” by Tore Grane Klausen et.al., Geology, March 2019: pubs.geoscienceworld.org/gsa/geology/article/47/5/470/569564/The-largest-delta-plain-in-Earths-history.
M. Michael Brady was educated as a scientist and, with time, turned to writing and translating.
This article originally appeared in the September 6, 2019, issue of The Norwegian American.