S U M M A R Y W phase is a long period phase arriving before S wave. It can be interpreted as superposition of the fundamental, first, second and third overtones of spheroidal modes or Rayleigh waves and has a group velocity from 4.5 to 9 km s−1 over a period range of 100–1000 s. The amplitude of long period waves better represents the tsunami potential of an earthquake. Because of the fast gro...

Earthquakes of large magnitude generally above M 7.0, occurring in shallow depths of seabed fault zones, cause rapid and vertical displacement of sea water. This results in the generation of tsunamis. The tsunamis in turn generate a series of deep ocean waves that have larger wavelengths, greater amplitude, period and velocity compared to normal waves. These waves with tremendous energy propaga...

-The fault parameters of the Guam earthquake of August 8, 1993 are estimated from seismological analyses, and the possibility of identifying the actual fault plane from tsunami waveforms is tested. The Centroid Moment Tensor solution of long-period surface waves shows one nodal plane shallowly dipping to the north and the other nodal plane steeply dipping to the south. The seismic moment is 3.5...

In some tsunami waves travelling over the ocean, such as the one approaching the eastern coast of Japan in 2011, the sea surface of the ocean is depressed by a small meter-scale displacement over a multi-kilometer horizontal length scale, lying in front of a positive elevation of comparable magnitude and length, which together constitute a down-up or “breather” wave. Shallow water theory shows ...

Tsunami wave generation by submarine landslides of a variable volume in a basin of variable depth is studied within the shallow-water theory. The problem of landslide induced tsunami wave generation and propagation is studied analytically for two specific convex bottom profiles (h∼ x4/3 and h∼ x4). In these cases the basic equations can be reduced to the constant-coefficient wave equation with ...

S U M M A R Y The Rudbar-Tarom earthquake of 1990 June 20 (M0 = 1.4 × 1027 dyn cm), the largest one in Iran over the past 35 yr, was accompanied by a small tsunami in the Caspian Sea, which produced run-ups of up to 2 m, and inundations of 1 km, reaffirming the existence of tsunami hazard along the Caspian shoreline, as suggested by historical reports. We present the results of a field survey, ...

Cover photograph – Panorama view on the north coast of Bonaire at Boka Kokolishi in March 2006 showing (from left to right), Caribbean Sea, modern sea cliff, scattered boulders and sand deposits on an elevated rock platform, and a paleo-seacliff. Wave swept zone and fresh sand deposits were products of Hurricane Ivan in September 2004. SUMMARY This report presents an overview of preliminary geo...

Earthquakes occurring at the Pacific Rim can trigger tsunamis that propagate across the ocean and can produce significant damages far away from the source. In French Polynesia, the Marquesas Islands are the most exposed to the far-field tsunami hazards, since they are not protected by any outer coral reef and since submarine slopes are less steep than in other islands. Between 1994 and 1996, fo...