when did the volcano nevado del ruiz erupt
Nevado del Ruiz During recorded history, eruptions have consisted primarily of a central vent eruption (in the caldera) followed by an explosive eruption, then lahars. Ruiz's earliest identified Holocene eruption was about 6660 BC, and further eruptions occurred in 1245 BC ± 150 years (dated through radiocarbon dating), about 850 BC, 200 BC ± 100 years, 350 AD ± 300 years, 675 AD ± 50 years, in 1350, 1541 (perhaps),[nb 1] 1570, 1595, 1623, 1805, 1826, 1828 (perhaps),[b] 1829, 1831, 1833 (perhaps),[b] 1845, 1916, December 1984 – March 1985, September 1985 – July 1991, and possibly in April 1994.[b] Many of these eruptions involved a central vent eruption, a flank vent eruption, and a phreatic (steam) explosion.[23] Ruiz is the second-most active volcano in Colombia after Galeras.[16]
Paris Peace Accords
Marcus Álvarez
New Madrid Seismic Zone Instruments were installed in and around the area in 1974 to closely monitor seismic activity. Since then, more than 4,000 earthquakes have been recorded, most of which were too small to be felt. On average, one earthquake per year is large enough to be felt in the area.