Siljan Ring Siljan Ring The Siljan Ring () is a prehistoric impact crater in Dalarna, central Sweden. It is one of the 15 largest known impact craters on Earth and the largest in Europe, with a diameter of about . The impact that created the Siljan Ring occurred when a meteorite collided with the Earth's surface during the Devonian period, about 376.8 ± 1.7 Ma. This coincides around the first Devonian extinction, the Kellwasser Event or Late Frasnian extinction at 376.1 Ma ± 1.6 Ma. The effects of the impact can clearly be seen in the bedrock in the area. The Cambrian,
Cyclone Mora International Airport were cancelled. Authorities attempted to evacuate 1 million people prior to landfall, however by May 29, only 300,000 had done so. Red Crescent volunteers and medical units were on alert as government offices in coastal zones closed. A meteorological office issued a warning for Chittagong and Cox’s Bazar as the cyclonic storm Mora headed towards Bangladesh. The Indian Meteorological Department issued Tropical cyclone warnings and watches for the Indian states of Mizoram, Nagaland, Manipur, West Bengal and Tripura. The Mizoram government expected that the cyclone could cause landslides and floods, so warnings were issued which advised residents to