Asama erupted in 1783 (Tenmei 3), causing widespread damage. The three-month-long plinian eruption that began on 9 May 1783, produced andesitic pumice falls, pyroclastic flows, lava flows, and enlarged the cone. The climactic eruption began on 4 August and lasted for 15 hours, and contained pumice falls and pyroclastic flows. The complex features of this eruption are explained by rapid deposits of coarse pyroclastic ash near the vent and the subsequent flows of lava; and these events which were accompanied by a high eruption plume which generated further injections of pumice into the air. 1982 eruption Explosive eruptions occurred at the summit of Asama volcano on 26 April. Fine ash fell in Tokyo, to the SE, for the first time in 23 years. 1983 eruptions An explosive eruption occurred on 8 April. Incandescent tephra was ejected, and ash fell from the volcano. 1995 earthquakes In April 1995, more than 1000 earthquakes were detected at the volcanic mountain. 2004 eruption A single vulcanian eruption occurred at Asama volcano at 11:02 UT on 1 September 2004. Incandescent blocks were ejected from the summit and caused many fires. The eruption sent ash and rock as far away as . 2008 eruptions Three small ash eruptions occurred at Asama volcano in August 2008. This was the first activity at the volcano since 2004. 2009 eruptions Mount Asama erupted in early February 2009, sending ash to a height of , and throwing rocks up to 1 km (⅝ mi) from the crater. Ash fall was reported in Tokyo, southeast of the volcano crater. On 16 February there were 13 recorded volcanic earthquakes and an eruption emitting smoke and ash in a cloud high. Mount Asama continued to have small eruptions, tremors and earthquakes in February and remained on level-3 alert (with a danger zone within 4 km (2½ mi) of the crater). Marking the span of Japan's history The eruptions of Mount Asama mark the span of Japan's recorded history, including: 2019, 2009, 2008, 2004, 2003, 1995, 1990, 1983, 1982, 1973, 1965, 1961, 1958–59, 1953–55, 1952, 1952, 1950–51, 1949, 1947, 1946, 1944–45, 1938–42, 1935–37, 1934, 1934, 1933, 1931–32, 1930, 1929, 1929, 1927–28, 1924, 1922, 1920–21, 1919, 1918?, 1917, 1916, 1915, 1914, 1909–14, 1908, 1908, 1907, 1907, 1906, 1905?, 1904, 1903, 1902, 1902, 1900–01, 1899, 1899, 1894, 1889, 1879, 1878?, 1875, 1869, 1815, 1803, 1803, 1783, 1779?, 1777, 1776, 1769, 1762, 1755, 1754, 1733, 1732, 1731,