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Microseismicity near the Indian Ocean triple junction
Author(s) -
Solomon Sean C.,
Mattaboni Paul J.,
Hester Richard L.
Publication year - 1977
Publication title -
geophysical research letters
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 2.007
H-Index - 273
eISSN - 1944-8007
pISSN - 0094-8276
DOI - 10.1029/gl004i012p00597
Subject(s) - seismology , triple junction , geology , seismometer , ridge , crest , induced seismicity , seismic moment , fault (geology) , geodesy , geophysics , physics , paleontology , quantum mechanics
During March 1976 a three‐component ocean bottom seismometer was dropped for two weeks near the RRR triple junction near 25°S, 70°E in the central Indian Ocean to monitor microseismicity. The seismometer, using a digital event recorder scheme, recorded 38 earthquakes, about half of which were local events within 5 to 40 km epicentral distance. These near events had nominal local magnitudes of 0 to 1.5, seismic moments of 10 17 to almost 10 19 dyne‐cm, and S wave corner frequencies of 15 to 25 Hz. The moment versus fault dimension relation for these earthquakes scales as for larger events on other spreading centers, suggesting similar stress drops. Thus any thermal or mechanical differences between the triple junction and other ridge crest and transform systems is not reflected in the character of locally generated earthquakes.