Earthquake Information

Page created by W. G. HuangCredit EMSCSummary:

MagnitudeMw 8.8RegionOFFSHORE MAULE, CHILE

Date time2010-02-27 at 06:34:14.1 UTCLocation35.89 S ; 73.04 WDepth30 kmDistances95 km N Talcahuano (pop 252,968 ; local time 03:34 2010-02-27) 65 km W Cauquenes (pop 31,362 ; local time 03:34 2010-02-27)

Earthquake Parameters201002270634Mw=8.8 D=30km2007111420070815200411152009052820100112Haiti earthquakeTaiwanPage created by W. G. Huang19600522Credit EMSC

Eurasian-Indian/Australian African Pacific South American North American Antarctica PhilippinesCaribbeanNazcaPacific

MAJOR TECTONIC PLATES OF THE WORLD Page created by W. G. HuangChile, like much of the west coast of South America, lies above an area of intense seismic activity and is no stranger to earthquakes. The nearby Nazca tectonic plate, which lies under the Pacific Ocean, is forced underneath the South American continental plate at a rate of about 4 cm a year. That may not sound a lot but it is enough to put huge strain on the earth's crust. The pressures are periodically released through earthquakes.

201002270634Mw=8.8 D=30km20071114200708152004111519600522M=9.520100227Mw=8.820071114Mw=7.719600522M=9.5NazcaPlate

Haze Over Santiao Following 8.8 Earthquake Page created by W. G. HuangCredit NASA

Tsunami Generation:

This animation by Prof. Miho Aoki from the University of Alaska Fairbanks Art Department provides a very nice look at how a tsunami can be generated by a subduction zone earthquake.

Page created by W. G. HuangCredit NOAA

The 1960 Chilean tsunami radiated outward from a subduction zone along the coast of Chile. Its waves reached Hawaii in 15 hours and Japan in 22 hours. Page created by W. G. HuangCredit USGS

The magnitude 9.5 earthquake in Chile on May 22, 1960 The magnitude 8.8 earthquake in Chile on Feb. 27, 2010Tsunami Maximum Amplitude Plot

Fast teleseismic body-wave source inversion Martin Valle (Goazur, IRD, Nice, France, vallee@geoazur.unice.fr) Jean Charlty (Goazur, CNRS, Nice, France, charlety@geoazur.unice.fr) Collaboration with A. Ferreira (UEA, Norwich,UK) and LDG/CEA (Paris, France) Method

We have deconvolved the compressive (P, PcP, PP) and transverse (SH,ScS) teleseismic waves recorded by FDSN-Geoscope stations to simultaneously retrieve the focal mechanism, moment magnitude and source time functions (Frequency band: 0.005Hz -0.17Hz).Page created by W. G. HuangCredit EMSC

Source parameters, uncertainties and agreement with teleseismic data. (Top left) Optimal values of moment magnitude, depth and focal mechanism. (Bottom left) Uncertainty analysis used to determine theacceptable values of dip, depth and magnitude (see values in the bottom). (Right) Agreement between data (black) and synthetics (red), both for compressive (i.e. P, PcP, PP) waves and transverse (i.e. S, ScS) waves (frequency band: 0.005-0.03Hz). Name of the station, azimuth, distance and maximum amplitude (in microns) are shown for each signal.Page created by W. G. HuangCredit EMSC

Broadband Source time functions (RSTFs), in the time and frequency domains. (Top left) Optimal values of moment magnitude, depth and focal mechanism. (Bottom left) Spectrum of the compressive RSTFs. The classical omega-2 slope is shown in the left part of the figure. (Right) Broadband RSTFs, in the time domain, for compressive waves. For each RSTF, the name of the station, its azimuth and epicentral distance are shown Page created by W. G. HuangCredit EMSC

Finite Fault Model Preliminary Result of the Feb 27, 2010 Mw 8.8 Maule, Chile Earthquake

Gavin Hayes, NEICDATA Process and Inversion

We used the GSN broadband waveforms downloaded from the NEIC waveform server. We analyzed 19 teleseismic broadband P waveforms, 8 broadband SH waveforms, and 32 long period surface waves selected based upon data quality and azimuthal distribution. Waveforms are first converted to displacement by removing the instrument response and then used to constrain the slip history based on a finite fault inverse algorithm (Ji et al, 2002). We use the hypocenter of the USGS (Lon.=-35.83 deg.; Lat.=-72.67 deg.). The fault planes are defined using the W-phase moment tensor solution of the NEIC. Page created by W. G. HuangCredit USGS

Cross-section of slip distribution Cross-section of slip distributionCross-section of slip distribution. The strike direction of fault plane is indicated by the black arrow and the hypocenter location is denoted by the red star. The slip amplitude are showed in color and motion direction of the hanging wall relative to the footwall is indicated by white arrows. Contours show the rupture initiation time in seconds. Page created by W. G. HuangCredit USGS

Moment Rate Function Source time function, describing the rate of moment release with time after earthquake origin. Page created by W. G. HuangCredit USGS

Comparison of teleseismic body waves. The data is shown in black and the synthetic seismograms are plotted in red. Both data and synthetic seismograms are aligned on the P or SH arrivals. The number at the end of each trace is the peak amplitude of the observation in micro-meter. The number above the beginning of each trace is the source azimuth and below is the epicentral distance. Page created by W. G. HuangCredit USGS

Comparison of long period surface waves. The data is shown in black and the synthetic seismograms are plotted in red. Both data and synthetic seismograms are aligned on the P or SH arrivals. The number at the end of each trace is the peak amplitude of the observation in micro-meter. The number above the beginning of each trace is the source azimuth and below is the epicentral distance. Page created by W. G. HuangCredit USGS

Surface projection of the slip distribution superimposed on ETOPO2. The black line indicates the major plate boundary [Bird, 2003]. Page created by W. G. HuangCredit USGS

The Chilean president, Michelle Bachelet, looks down at damaged houses in ConcepcionPage created by W. G. HuangCredit Guardian Limitted

Residents gather their belongings near a fishing boat washed ashore by a wave in Talcahuano Port Credit Guardian LimittedPage created by W. G. Huang

Broadband downhole seismic array in Taipei BasinPage created by W. G. Huang

The particle velocities recorded at 101B at level -100 meters.