Science of Tsunami Hazards (May 2020)
SEISMOTECTONICS AND MECHANISMS OF TSUNAMI GENERATION ALONG ACTIVE BOUNDARIES OF YOUNG, MARGINAL SEA BASINS AND SPREADING RIDGES OF THE SOLOMON ISLANDS REGION – Case Study: The Earthquake and Tsunami of 1 April 2007 in the Solomon Islands
Abstract
The Solomon Islands region is characterized by high seismic activity. During the last 100 years there have been numerous strong earthquakes with periodic variation of recurrence. Some of them on either side of the Solomon Island Volcanic Arc have generated destructive tsunamis not only in the Solomons but also in neighboring Papua New Guinea. Most of the larger magnitude earthquakes occur on the northeast side of the Solomon Island Arc and Trench along a 350 km segment, close to the Islands of Guadalcanal and San Christobal. On the northeast side of the Solomon Island Arc larger ruptures of adjacent slabs are possible which could involve the New Ireland segment or the North Solomon Trench. However, significant earthquake activity occurs also along the southeast side of the Solomon Island Arc, but not as frequently. A great magnitude 8.1 earthquake on 1 April 2007 in the southeast region generated a tsunami that was particularly destructive in the Islands of the New Georgia Group of the Northwest Solomon Islands. The present study examines the impact of this earthquake and of the tsunami it generated, and reviews the seismotectonic setting of the Solomon Islands region for the purpose of understanding the regional mechanisms of tsunami generation along the active boundaries of young, marginal sea basins and spreading ridges.
