FY 2003

Hydrothermal temperature changes at the southern Juan de Fuca Ridge associated with a Mw 6.2 Blanco Transform earthquake

Dziak, R.P., W.W. Chadwick, Jr., C.G. Fox, and R.W. Embley

Geology, 31(2), 119–122 (2003)

The regional impact of transform seismicity on ridge-crest hydrothermal venting and ridge-transform dynamics is investigated using a June 1-7, 2000, Blanco Transform earthquake sequence. The mainshock (M 6.2) and 170 foreshocks and aftershocks were located using T waves recorded on U.S. Navy hydrophones, and indicate that the active transform fault may be farther south than in previous tectonic models. During the earthquake sequence, two temperature probes were deployed in black smoker chimneys at the Vent1 and Plume hydrothermal fields along the southern Juan de Fuca Ridge. These two hydrothermal systems are ~39 km northwest of the mainshock