SUMMARY:Type: shield |
GEOLOGIC HISTORYMt. Siple is a 3110 m-high shield volcano with a 4-5 km-wide summit caldera and is located at the SW terminus of the Getz Ice Sheet on Siple Island (Bakutis Coast). Mount Siple is a youthful-looking shield volcano that forms an island along the Pacific Ocean coast of Antarctica's Marie Byrd Land. The massive 1,800 km3 volcano is truncated by a 4-5 km summit caldera and is ringed by tuff cones at sea level. The volcano's base is exposed at sea level. A basalt sample from the base of the volcano yielded a K-Ar age of about 2 million years. Its lack of dissection in a coastal area more susceptible to erosion than inland Antarctic volcanoes, and the existence of a satellite cone too young to date by the K-Ar method, suggest a possible Holocene age. Historic Activity: No previous historic eruptions have been reported. Recent Activity: Apparent ash plumes were detected by NOAA 10 satellite imagery on Sept. 18, 1988 and again on Oct. 4. The Oct. 4 plume extended about 160-170 km WNW and was well defined, but it was uncertain whether the plume originated from the volcano's summit or base. Later observations showed no evidence of an eruption and the plumes are believed to have resulted from meteorological effects. Data Sources
|
ADDITIONAL INFORMATION
|
|
Last Update: 2/13/00 |