Geophysical observations from the 2011 moment magnitude (M_w) 9.0 Tohoku-Oki, Japan earthquake allow exploration of a rare large event along a subduction megathrust. Models for this event indicate that the distribution of coseismic fault slip exceeded 50 meters in places.
 Sources of high-frequency seismic waves delineate the edges of the
 deepest portions of coseismic slip and do not simply correlate with the
 locations of peak slip. Relative to the M_w 8.8 2010 Maule, Chile
 earthquake, the Tohoku-Oki earthquake was deficient in high-frequency
 seismic radiation-a difference that we attribute to its relatively
 shallow depth. Estimates of total fault slip and surface secular strain
 accumulation on millennial time scales suggest the need to consider the
 potential for a future large earthquake just south of this event.

https://science.sciencemag.org/content/sci/332/6036/1421.full.pdf

The 2011 Magnitude 9.0 Tohoku-Oki Earthquake: Mosaicking the Megathrust from Seconds to Centuries

Subduction zone plate boundary megathrust faults accommodate relative plate motions with spatially varying sliding behavior. The 2004 Sumatra-Andaman (M_w 9.2), 2010 Chile (Mw 8.8), and 2011 Tohoku (M_w 9.0) great earthquakes had similar depth variations in seismic wave radiation across their wide rupture zones – coherent teleseismic short-period radiation preferentially emanated from the deeper portion of the megathrusts whereas the largest fault displacements occurred at shallower depths but produced relatively little coherent short-period radiation. We represent these and other depth-varying seismic characteristics with four distinct failure domains extending along the megathrust from the trench to the downdip edge of the seismogenic zone. We designate the portion of the megathrust less than 15 km below the ocean surface as domain A, the region of tsunami earthquakes. From 15 to ∼35 km deep, large earthquake displacements occur over large-scale regions with only modest coherent short-period radiation, in what we designate as domain B. Rupture of smaller isolated megathrust patches dominate in domain C, which extends from ∼35 to 55 km deep. These isolated patches produce bursts of coherent short-period energy both in great ruptures and in smaller, sometimes repeating, moderate-size events. For the 2011 Tohoku earthquake, the sites of coherent teleseismic short-period radiation are close to areas where local strong ground motions originated. Domain D, found at depths of 30–45 km in subduction zones where relatively young oceanic lithosphere is being underthrust with shallow plate dip, is represented by the occurrence of low-frequency earthquakes, seismic tremor, and slow slip events in a transition zone to stable sliding or ductile flow below the seismogenic zone.

http://authors.library.caltech.edu/31607/1/Lay2012p18168J_Geophys_Res-Sol_Ea.pdf

Depth‐varying rupture properties of subduction zone megathrust faults

Journal of researches into the natural history and geology of the countries visited during the voyage of H.M.S. Beagle round the world under the command of captain Fitz Roy

Toward understanding tectonic control on the Mw 8.8 2010 Maule Chile earthquake

Coupled tectonic evolution of Andean orogeny and global climate

Large earthquakes produce crustal deformation that can be quantified by geodetic measurements, allowing for the determination of the slip distribution on the fault. We used data from Global Positioning System (GPS) networks in Central Chile to infer the static deformation and the kinematics of the 2010 moment magnitude ( M w) 8.8 Maule megathrust earthquake. From elastic modeling, we found a total rupture length of ~500 kilometers where slip (up to 15 meters) concentrated on two main asperities situated on both sides of the epicenter. We found that rupture reached shallow depths, probably extending up to the trench. Resolvable afterslip occurred in regions of low coseismic slip. The low-frequency hypocenter is relocated 40 kilometers southwest of initial estimates. Rupture propagated bilaterally at about 3.1 kilometers per second, with possible but not fully resolved velocity variations.

https://science.sciencemag.org/content/sci/332/6036/1417.full.pdf

The 2010 Mw 8.8 Maule megathrust earthquake of Central Chile, monitored by GPS.

Rupture kinematics of this very large earthquake were obtained from high-resolution Global Positioning System data. Large earthquakes produce crustal deformation that can be quantified by geodetic measurements, allowing for the determination of the slip distribution on the fault. We used data from Global Positioning System (GPS) networks in Central Chile to infer the static deformation and the kinematics of the 2010 moment magnitude (Mw) 8.8 Maule megathrust earthquake. From elastic modeling, we found a total rupture length of ~500 kilometers where slip (up to 15 meters) concentrated on two main asperities situated on both sides of the epicenter. We found that rupture reached shallow depths, probably extending up to the trench. Resolvable afterslip occurred in regions of low coseismic slip. The low-frequency hypocenter is relocated 40 kilometers southwest of initial estimates. Rupture propagated bilaterally at about 3.1 kilometers per second, with possible but not fully resolved velocity variations.

/pdf/supporting-online-material-for-the-2010-mw-8-8-maule-22a9a7bhwr.pdf

A. Pavez

Papers

The 2010 Mw 8.8 Maule megathrust earthquake of Central Chile, monitored by GPS.

Supporting Online Material for The 2010 Mw 8.8 Maule Megathrust Earthquake of Central Chile, Monitored by GPS