Tsunami generation by an earthquake is generally modeled water surface displacement identical to the vertical deformation of ocean bottom due faulting. The effect horizontal usually neglected. However, when tsunami source on a steep slope and large relative displacement, becomes significant. We show this for two recent earthquakes which generated much larger tsunamis than expected from seismic waves. In case 1994 June 2 Java, Indonesia, earthquake, focal mechanism was very shallow dipping...

We present a narrative of the eruptive events culminating in cataclysmic January 15, 2022 eruption Hunga Tonga-Hunga Ha'apai Volcano by synthesizing diverse preliminary seismic, volcanological, sound wave, and lightning data available within first few weeks after occurred. The hour activity produced fast-propagating tsunami waves, long-period seismic loud audible infrasonic exceptionally intense volcanic an unsteady plume that transiently reached—at 58 ​km—the Earth's mesosphere. Energetic...

The June 15, 1896 Sanriku earthquake generated devastating tsunamis with the maximum run‐up of 25 m and caused worst tsunami disaster in history Japan, despite its moderate surface wave magnitude (M s =7.2) weak seismic intensity. This is a typical earthquake, which generates anomalously larger than expected from waves. Previously proposed mechanisms earthquakes include submarine slumping slow rupture accretionary wedge or subducted sediments. In this paper, we estimate fault parameters by...

We propose a method for near‐field tsunami forecasting from data acquired by cabled offshore ocean bottom meters (OBTMs) in real time. first invert waveforms recorded at OBTMs to estimate the spatial distribution of initial sea‐surface displacements source region without making any assumptions about fault geometry and earthquake magnitude. Then, we synthesize coastal estimated displacement distribution. To improve reliability forecasting, use updated OBTM repeat forecast calculation 1‐min...

We propose a method of tsunami waveform inversion to accurately estimate source by incorporating the effect permanent seafloor deformation recorded ocean‐bottom pressure gauges (OBPGs) within region. developed general expression water‐depth fluctuation at an OBPG following arbitrary spatiotemporal distribution. By assuming that coseismic rupture propagates with infinite velocity, can be reduced equation relating observed waveforms initial sea‐surface displacement using Green's function...

The 2010 Mentawai earthquake (magnitude 7.7) generated a destructive tsunami that caused more than 500 casualties in the Islands, west of Sumatra, Indonesia. Seismological analyses indicate this was an unusual "tsunami earthquake," which produces much larger tsunamis expected from seismic magnitude. We carried out field survey to measure heights and inundation distances, inversion waveforms estimate slip distribution on fault, modeling compare measured simulated heights. at eight locations...

Abstract A large eruption of the Hunga Tonga-Hunga Haʻapai volcano in Tonga on January 15, 2022 generated air–sea coupled tsunamis observed at ocean-bottom pressure sensor network along Japan Trench (S-net) Japan. Initial from eruption, detected by 106 sensors, were well modeled an tsunami simulation, with a simple atmospheric pulse as sine function, having half-wavelength 300 km and peak amplitude 2 hPa. one-dimensional simulation bathymetry shows that input short 50 km, which is shorter...

The tsunami caused by the Tonga submarine volcanic eruption that occurred at 13:15 Japan Time (JST) on January 15, 2022, exposed a blind spot in Japan's monitoring and warning system, which was established 1952 for local tsunamis expanded to distant after 1960 Chile tsunami. This paper summarizes how system responded unprecedented tsunami, actual evacuation process, damage it Japan. Initially, from expected arrive approximately midnight with amplitudes of less than 20 cm. However, series...

The 1896 Sanriku earthquake was one of the most devastating tsunami earthquakes, which generated an anomalously larger than expected from its seismic waves. Previous studies indicate that occurred beneath accretionary wedge near trench axis. It pointed out recently sediments a toe inner slope with large horizontal movement due to might have caused additional uplift. In this paper, effect uplift generation is quantified. We estimate slip by numerically computing tsunamis and comparing their...

Coseismic slip distribution on the fault plane of 1944 Tonankai earthquake is estimated from inversion tsunami waveforms. Three improvements a previous study [ Satake, 1993] are made. These are: (1) smaller subfaults used to resolve detailed distribution; (2) sub faults fit better plate interface geometry; and (3) finer more accurate bathymetry data used. The result shows that maximum about 3 m occurred off Shima peninsula. total seismic moment be 2.0 × 10 21 Nm (M w 8.2). confirms did not...

Tsunami heights greater than 4 m were observed at several coastal tide-gauge stations during the tsunami generated by 2011 off Pacific coast of Tohoku Earthquake (Mw 9.0), causing thousands casualties and damaging infrastructure along Japan. We retrospectively applied an algorithm near-field forecasting to data that recorded various offshore 5–10 min before reached nearest its source. inverted waveform estimate distribution initial sea-surface height, then waveforms synthesized from...

Coseismic slip distribution on the fault plane of 1946 Nankai earthquake (Mw 8.3) was estimated from inversion tsunami waveforms. The following three improvements previous study (Satake, 1993) were made. (1) Larger number smaller subfaults is used; (2) fit better to slab geometry; and (3) more detailed bathymetry data are used. result shows that agreement between observed synthetic waveforms greatly improved study. In western half source region off Shikoku, a large about 6 m occurred near...

Traveling ionospheric disturbances generated by an epicentral ground/sea surface motion, associated with Rayleigh‐waves as well post‐seismic 4‐minute monoperiodic atmospheric resonances and other‐period oscillations have been observed in large earthquakes. In addition, a giant tsunami after the subduction earthquake produces hole which is widely sudden depletion of total electron content (TEC) hundred kilometer scale lasts for few tens minutes over source area. The tsunamigenic detected TEC...

Abstract Existing tsunami early warning systems in the world can give either one or a combination of estimated arrival times, heights, qualitative forecasts before hits near‐field coastlines. A future system should be able to provide reliable inundation forecast on high‐resolution topography within short time period. Here we describe new methodology for forecasting. In this method, precomputed and waveform database is required. After information about source estimated, waveforms at nearshore...

The slip distribution of the 2003 Tokachi-oki earthquake is estimated from 11 tsunami waveforms recorded at 9 tide gauges in southern Hokkaido and eastern Tohoku coasts two ocean bottom tsunami-meters (pressure gauges) off Kamaishi, Tohoku. largest 4.3 m on subfault located Hiroo. A large 2.1 also near Kushiro. total seismic moment 1.0 × 1021 Nm. waveform inversion similar to deduced by Yamanaka Kikuchi (2003) teleseismic body waves. rupture area western part 1952 Hirata et al. (2003).

Research Article| May 01, 2013 Comparison of Earthquake Source Models for the 2011 Tohoku Event Using Tsunami Simulations and Near‐Field Observations Breanyn T. MacInnes; MacInnes Institute Seismology Volcanology, Hokkaido University, N10W8 Kita‐ku, Sapporo, 060‐0810, Japanmacinnes@geology.cwu.edu *Now at Department Geological Sciences, Central Washington 400 E. University Way, Ellensburg, 98926. Search other works by this author on: GSW Google Scholar Aditya Riadi Gusman; Gusman Randall J....

Abstract The lateral (along trench axis) variation in the mode of large earthquake occurrence near northern Japan Trench is explained by surface roughness subducting plate. ocean bottom well correlated with large‐earthquake occurrence. region where smooth with‘typical’large underthrust earthquakes (e.g. 1968 Tokachioki event) deeper part seismogenic plate interface, and there are no shallow (aseismic zone). rough (well‐developed horst graben structure) normal faulting 1933 Sanriku outer‐rise...

Abstract Rupture process of the 2004 Sumatra-Andaman earthquake is estimated using tsunami waveforms observed at tide gauges and coseismic vertical deformation along coast. The average rupture speed to be 1.7 km/s from waveform analysis. extends about 1200 km toward north-northwest Andaman trough. largest slip 23 m on plate interface off northwest coast in Aceh province Sumatra. Another large 21 also beneath north Simeulue Island Indonesia. other 10–15 near Little Car Nicobar Inlands. total...

Abstract Satellite altimetry measurements of sea surface heights for the first-time captured Indian Ocean tsunami generated from December 2004 great Sumatra earthquake. Analysis height profile suggests that source, or seafloor deformation, earthquake propagated to north at an extremely slow speed less than 1 km/sec on average entire 1300-km-long segment along northern Sumatra-Nicobar-Andaman Trench. The propagation produces a very long duration tens minutes, longer source estimated (480–500...