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Geological Survey research 1972, Chapter C

Professional Paper 800-C

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Abstract

Eruptions of basaltic lava in 1969 filled Alae Crater with a complex lava lake, and subsequent overflows built the southeastern crater rim 24m higher. The lake partly drained in August 1970, refilled during the next 3 months, and partly drained again in February and March 1971. The solidified crust of the lake subsided 13 m during the 1970 draining and 23 m during the 1971 draining. The volume of draining was about 106 m3 during both events. The August 1970 draining took place when a lava tube, located 2-3m above the base of the new lava overlying the crater rim, reopened accompanying rapid addition of lava beneath the crust of the lake. The February-March 1971 draining was more complicated; the pre-February lake crust sank into the molten lake because of the weight of new overlying flows. This subsidence displaced Wlderlying molten lava upward and. out of the lake through the outlet tube. The elevation of the base of the lake crust after both draining events was controlled in a crudely hydrostatic fashion by the elevation of the outlet tube.

Additional publication details

Publication type:
Report
Publication Subtype:
USGS Numbered Series
Title:
Geological Survey research 1972, Chapter C
Series title:
Professional Paper
Series number:
800
Chapter:
C
Year Published:
1972
Language:
English
Publisher:
U.S. Government Printing Office
Contributing office(s):
Pennsylvania Water Science Center
Description:
282 p.
Larger Work Type:
Report
Larger Work Subtype:
USGS Numbered Series
Larger Work Title:
Geological survey research, 1972