As a scientist working in the active tectonics of the Peruvian Andes - funded through the Lawrence Livermore National Laboratory's Institute for Geophysics and Planetary Physics - Farber was asked by colleagues if he could participate in a rapid response team to map the damage of the seismic deformation and install a system of geodetic stations.
He jumped at the opportunity to install a Global Positioning System (GPS) network to capture the post-seismic response and collected critical geological data for the understanding of the inter-plate dynamics of one of the Earth's largest subduction zones - the Central Peru Megathrust.
In a new paper appearing in the May 6 edition of the journal Nature, Farber and international colleagues determined that the seismic slip on the Central Peru Megathrust is not dependent on earthquakes alone. As it turns out, movement along this subduction zone is caused by earthquakes as well as non-seismic (aseismic) related slip from steady or transient creep between or directly after earthquakes.
"Active faults are made up of areas that slip mostly during earthquakes and areas that mostly slip aseismically," Farber said. "The size, location and frequency of earthquakes that a megathrust can generate depend on where and when aseismic creep is taking place."
The 8.0 Pisco earthquake that occurred in 2007 ruptured the subduction interface - where load-bearing flat surfaces butt up - between the Nazca plate and the South American plate, an area that subducts about 6 centimeters per year. In this event, two distinct areas moved 60 seconds apart in a zone that had remained locked in between earthquakes. The event also triggered aseismic frictional afterslip on two adjacent areas.
The most prominent afterslip coincides with the Nazca ridge subduction, which seems to have repeatedly acted as a barrier to seismic rupture propagation in the past.
To sum up, aseismic (non-earthquake producing) slip accounts for as much as 50 percent to 70 percent of the slip on this portion of the megathrust in central Peru. Because much of the interface displacement is taken up aseismically, an earthquake the size of the 2007 earthquake is estimated to occur only every 250 years.
Other collaborators included those from: Institut de Recherche pour le Développement, the Instituto Geofisico del Peru, California Institute of Technology, Géosciences Azur, University of California Santa Cruz and Université Paul Sabatier/CNRS/IRD.
Founded in 1952, Lawrence Livermore National Laboratory (www.llnl.gov) is a national security laboratory that develops science and engineering technology and provides innovative solutions to our nation's most important challenges. Lawrence Livermore National Laboratory is managed by Lawrence Livermore National Security, LLC for the U.S. Department of Energy's National Nuclear Security Administration.
Anne Stark | EurekAlert!
From volcano's slope, NASA instrument looks sky high and to the future
27.04.2017 | NASA/Goddard Space Flight Center
Penn researchers quantify the changes that lightning inspires in rock
27.04.2017 | University of Pennsylvania
More and more automobile companies are focusing on body parts made of carbon fiber reinforced plastics (CFRP). However, manufacturing and repair costs must be further reduced in order to make CFRP more economical in use. Together with the Volkswagen AG and five other partners in the project HolQueSt 3D, the Laser Zentrum Hannover e.V. (LZH) has developed laser processes for the automatic trimming, drilling and repair of three-dimensional components.
Automated manufacturing processes are the basis for ultimately establishing the series production of CFRP components. In the project HolQueSt 3D, the LZH has...
Reflecting the structure of composites found in nature and the ancient world, researchers at the University of Illinois at Urbana-Champaign have synthesized thin carbon nanotube (CNT) textiles that exhibit both high electrical conductivity and a level of toughness that is about fifty times higher than copper films, currently used in electronics.
"The structural robustness of thin metal films has significant importance for the reliable operation of smart skin and flexible electronics including...
The nearby, giant radio galaxy M87 hosts a supermassive black hole (BH) and is well-known for its bright jet dominating the spectrum over ten orders of magnitude in frequency. Due to its proximity, jet prominence, and the large black hole mass, M87 is the best laboratory for investigating the formation, acceleration, and collimation of relativistic jets. A research team led by Silke Britzen from the Max Planck Institute for Radio Astronomy in Bonn, Germany, has found strong indication for turbulent processes connecting the accretion disk and the jet of that galaxy providing insights into the longstanding problem of the origin of astrophysical jets.
Supermassive black holes form some of the most enigmatic phenomena in astrophysics. Their enormous energy output is supposed to be generated by the...
The probability to find a certain number of photons inside a laser pulse usually corresponds to a classical distribution of independent events, the so-called...
Microprocessors based on atomically thin materials hold the promise of the evolution of traditional processors as well as new applications in the field of flexible electronics. Now, a TU Wien research team led by Thomas Müller has made a breakthrough in this field as part of an ongoing research project.
Two-dimensional materials, or 2D materials for short, are extremely versatile, although – or often more precisely because – they are made up of just one or a...
20.04.2017 | Event News
18.04.2017 | Event News
03.04.2017 | Event News
27.04.2017 | Life Sciences
27.04.2017 | Physics and Astronomy
27.04.2017 | Earth Sciences