THE RESPONSE OF MONTEREY BAY TO THE GREAT TOHOKU EARTHQUAKE OF 2011

• Main Authors: D. Carroll, T. S. Murty, L. C. Breaker, W. J. Teague
• Format: Article
• Language: English
• Published: Tsunami Society International 2011-01-01
• Series: Science of Tsunami Hazards
• Subjects: Great Tohoku earthquake; Monterey Bay; damage report; singular spectrum analysis; seiche modes
• Online Access: http://tsunamisociety.org/303BreakerEtAl.pdf

The response of Monterey Bay to the Great Tohoku earthquake of 2011 is examined in this study. From a practical standpoint, although the resulting tsunami did not cause any damage to the open harbors at Monterey and Moss Landing, it caused extensive damage to boats and infrastructure in Santa Cruz Harbor, which is closed to surrounding waters. From a scientific standpoint, the observed and predicted amplitudes of the tsunami at 1 km from the source were 21.3 and 22.5 m based on the primary arrival from one DART bottom pressure recorder located 986 km ENE of the epicenter. The predicted and observed travel times for the tsunami to reach Monterey Bay agreed within 3%. The predicted and observed periods of the tsunami-generated wave before it entered the bay yielded periods that approached 2 hours. Once the tsunami entered Monterey Bay it was transformed into a seiche with a primary period of 36-37 minutes, corresponding to quarter-wave resonance within the bay. Finally, from a predictive standpoint, major tsunamis that enter the bay from the northwest, as in the present case, are the ones most likely to cause damage to Santa Cruz harbor.