GoKawiilThe Nördlinger Ries (German pronunciation: [ˈnœʁtlɪŋɐ ˈʁiːs] ) is an impact crater [1] and large circular depression in western Bavaria and eastern Baden-Württemberg . It is located north of the Danube in the district of Donau-Ries . The city of Nördlingen is located within the depression, about 6 kilometres (3.7 mi) south-west of its centre.
After the impact, the crater filled with water, forming a lake ~400 km 2 in area, almost the size of Lake Constance . [20] The lake silted up after about two million years. The present Ries basin was only exposed by erosion during the Ice Ages. [21]
Stone buildings in Nördlingen contain millions of tiny diamonds , all less than 0.2 mm (0.008 in) across. The impact that caused the Nördlinger Ries crater created an estimated 72,000 tonnes (72,000,000 kg ) of them when it impacted a local graphite deposit. Stone from this area was quarried and used to build the local buildings. [19]
The Ries crater impact event is believed to be the source of moldavite tektites found in southern Bohemia and Moravia ( Czech Republic ). [17] The tektite melt originated from a sand-rich surface layer that was ejected to distances up to 450 km (280 mi) downrange of the crater. The shape of the strewnfield suggests that the direction of impact was from the west-southwest . [18]
Recent computer modeling of the impact event indicates that the impactors probably had diameters of about 1.5 km (4,900 ft) (Ries) and 150 m (490 ft) (Steinheim), had a pre-impact separation of some tens of kilometers, and impacted the target area at an angle around 30 to 50 degrees from the surface in a west-southwest to east-northeast direction. [ citation needed ] The impact velocity is thought to have been about 20 km/s (72,000 km/h; 45,000 mph). [ citation needed ] The resulting explosion had the power of 40 million Hiroshima bombs , an energy of roughly 2.4×10 21 joules . [ citation needed ]
Another impact crater, the much smaller (3.8 km (2.4 mi) diameter) Steinheim crater , [15] is located about 42 km (26 mi) west-southwest from the center of Ries. It had previously been thought that the two craters formed simultaneously by the impact of a binary asteroid 14.8 million years ago, but a study published in 2020 suggests that Steinheim could actually be about 500,000 years younger than Nördlinger Ries . [16]
The Ries impact crater was a rampart crater , thus far a unique finding on Earth. [14] Rampart craters have almost exclusively been found on Mars . Rampart craters exhibit a fluidized ejecta flow after the impact of the meteorite, most simply compared to a bullet fired into the mud, with the ejecta resembling a mudflow .
The depression is a meteorite impact crater formed 14.808 ± 0.038 million years ago in the Miocene . [4] [5] The crater is most commonly referred to simply as the Ries crater or the Ries . The original crater rim had an estimated diameter of 24 km (15 mi). The present floor of the depression is about 100 to 150 m (330 to 490 ft) below the eroded remains of the rim.
Impact [ edit ]
The Ries impact (also known as the Ries event) was an asteroid impact that occurred approximately 15 million years ago in what is now southern Germany.[22] The resulting impact crater, the Nördlinger Ries, has a diameter of about 24 km (15 mi), indicating the release of an enormous amount of energy. The nearby Steinheim Basin and a number of smaller craters on the Franconian Jura and in the Lake Constance area are, according to more recent findings, not contemporaneous with the Nördlinger Ries and are therefore not part of the Ries event.[23]
... continue reading