Breathing of the seafloor: Tidal correlations of seismicity at Axial volcano

Publication Type  Journal Article
Year of Publication  2002
Authors  Tolstoy, M.; Vernon, F. L.; Orcutt, J. A.; Wyatt, F. K.
Journal Title  Geology
Volume  30
Issue  6
Pages  503-506
Journal Date  Jun
ISBN Number  0091-7613
Accession Number  ISI:000176152100005
Key Words  tides; earthquakes; correlations; axial seamount; de-fuca ridge; kilauea volcano; earth tides; floor; hawaii; ocean

Tidal effects on seafloor microearthquakes have been postulated, but the search has been hindered by a lack of continuous long-term data sets. Making this observation is further complicated by the need to distinguish between Earth and ocean tidal influences on the seafloor. In the summer of 1994, a small ocean-bottom seismograph array located 402 microseismic events, over a period of two months, on the summit caldera of Axial volcano on the Juan de Fuca Ridge. Harmonic tremor was also observed on all instruments, and Earth and ocean tides were recorded on tiltmeters installed within the seismometer packages. Microearthquakes show a strong correlation with tidal lows, suggesting that faulting is occurring preferentially when ocean loading is at a minimum. The harmonic tremor, interpreted as the movement of superheated fluid in cracks, also has a tidal periodicity.


561QCTimes Cited:24Cited References Count:18

URL  <Go to ISI>://000176152100005