Question: What area once connected Great Britain to continental Europe, and is thought to have been submerged around 6,200 BCE by a massive landslide along 290 km of the continental shelf?

Passages:
The North Sea is a marginal sea of the Atlantic Ocean located between Great Britain, Scandinavia, Germany, the Netherlands, Belgium, and France.  An epeiric (or "shelf") sea on the European continental shelf, it connects to the ocean through the English Channel in the south and the Norwegian Sea in the north.  It is more than 970 km long and 580 km wide, with an area of around 570000 km2 . The Siberian Shelf, one of the Arctic Ocean coastal shelves (such as the Milne Ice Shelf), is the largest continental shelf of the Earth, a part of the continental shelf of Russia.  It extends from the continent of Eurasia in the general area of North Siberia (hence the name) into the Arctic Ocean.  It stretches to 1500 km offshore.  It is relatively shallow, with average depth of 100 m.  A number of islands are within the shelf, including the Wrangel Island, Novaya Zemlya, and the New Siberian Islands. NOGAT ("Northern Offshore Gas Transport") is a natural gas pipeline system, which connects Dutch continental shelf with an onshore gas plant and terminal at Den Helder, the Netherlands.  The system is operational since 1992.  The Danish continental shelf pipeline system is connected to the NOGAT through the Tyra West – F3 pipeline and the German continental shelf pipeline system is connected to the NOGAT through A6-F3 pipeline. Gassco is a Norwegian state owned company that operates 7800 km of natural gas pipes transporting annually of 100 billion cubic meter (bcm) of natural gas from the Norwegian continental shelf to Continental Europe and Great Britain. Doggerland was an area now beneath the southern North Sea that connected Great Britain to continental Europe during and after the last glacial period.  It was flooded by rising sea levels around 6,500–6,200 BCE.  Geological surveys have suggested that it stretched from Britain's east coast to the Netherlands and the western coasts of Germany and the peninsula of Jutland.  It was probably a rich habitat with human habitation in the Mesolithic period, although rising sea levels gradually reduced it to low-lying islands before its final submergence, possibly following a tsunami caused by the Storegga Slide. Perth Canyon is a submarine canyon located on the edge of the continental shelf off the coast of Perth, Western Australia, approximately 22 km west of Rottnest Island.  It was carved by the Swan River, probably before the Tertiary, when this part of the continental shelf was above sea level.  It is an average of 1.5 km deep and 15 km across, making it similar in dimension to the Grand Canyon. The three Storegga Slides are considered to be amongst the largest known landslides.  They occurred under water, at the edge of Norway's continental shelf in the Norwegian Sea, approximately 6225–6170 BCE.  The collapse involved an estimated 290 km length of coastal shelf, with a total volume of 3500 km3 of debris, which caused a very large tsunami in the North Atlantic Ocean. The Pacific Ocean Shelf Tracking Project (POST) is a field project of the Census of Marine Life that researches the behavior of marine animals through the use of ocean telemetry and data management systems.  This system of telemetry consists of highly efficient lines of acoustic receivers that create sections of the continental shelf along the coast of the Pacific Northwest.  The acoustic receivers pick up signals from the tagged animals as they pass along the lines, allowing for the documentation of movement patterns.  The receivers also allow for the estimation of parameters such as swimming speed and mortality.  The trackers sit on the seabed of the continental shelf and in the major rivers of the world.  This method can be used to improve fishing skills and management. The Orango Islands National Park (Portuguese: "Ilhas de Orango" ) is found in Guinea-Bissau.  It was established on 1 December 2000.  This site is 1582 km² (terrestrial)and 94,235.00 km² (marine).  The area covers the southern part including Orango and Orangozinho along with the western islands and the marine portion up to around 150 to 200 km within the Bijagos Archipelago (much of its Bijagos portion of the continental shelf) up to the areas mainly 2,000 meters deep outside the continental shelf.  The park is administered by : Instituto da Biodiversidade e das Áreas Protegidas da Guiné-Bissau (Biodiversity Institute and Protected Areas of Guinea-Bissau). Tyra West – F3 pipeline is a 100 km long natural gas submarine pipeline connecting Danish and Dutch continental shelf pipeline systems.  It facilitates the export of Danish gas into North West Europe.  The 660 mm pipeline, which cost over US$200 million, runs from the Maersk-operated Tyra West platform on the Danish continental shelf to the F3 – FB platform on the Dutch continental shelf.  From F3 – FB platform, gas is fed through the NOGAT pipeline system to the Netherlands natural gas hub in Den Helder.

Supporting sentences:
Doggerland was an area now beneath the southern North Sea that connected Great Britain to continental Europe during and after the last glacial period.  It was probably a rich habitat with human habitation in the Mesolithic period, although rising sea levels gradually reduced it to low-lying islands before its final submergence, possibly following a tsunami caused by the Storegga Slide. The three Storegga Slides are considered to be amongst the largest known landslides.  The collapse involved an estimated 290 km length of coastal shelf, with a total volume of 3500 km3 of debris, which caused a very large tsunami in the North Atlantic Ocean.