Whales living within seismically active regions are subject to intense disturbances
from strong sounds produced by earthquakes that can kill or injure individuals.
Nishimura & Clark (1993) relate the possible effects of underwater earthquake noise
levels in marine mammals, adducing that T-phase source signal level (10- to 30- Hz
range) can exceed 200 dB re: 1 µPa at 1 m, for a magnitude 4-5 earthquake, sounds
audible to fin whales which produce low frequency sounds of 16-20/25-44 Hz over
0.5-1s, typically of 183 dB re: 1 µPa at 1 m. Here we present the response of a fin
whale to a 5.5 Richter scale earthquake that took place on 22 February 2005, in
the Gulf of California. The whale covered 13 km in 26 min (mean speed = 30.2 km/
h). We deduce that the sound heard by this whale might have triggered the costly
energy expenditure of high speed swimming as a seismic-escape response. These
observations support the hypothesis of Richardson et al. (1995) that cetaceans may
flee from loud sounds before they are injured, when exposed to noise in excess of 140
dB re: 1 µPa 1 m.
earthquake, Balaenoptera physalus, Gulf of California