SRL publishes focus section on Subduction Zone processes in the Americas

September 05, 2019

The eastern Pacific Ocean margin stretching from Mexico to southern Chile offers seismologists a "natural laboratory" in which to study and test ideas about the processes of subduction zones, which are associated with some of the world's largest recorded earthquakes in the region, as well as phenomena such as volcanism and tsunami generation.

In a focus section published in Seismological Research Letters, researchers from around the globe share what they've learned from an unprecedented amount of data collected in the Latin American Subduction Zone over the past two decades. In their introduction to the section, editors Carlos A. Vargas of the Universidad Nacional de Colombia at Bogota, Susan L. Beck of the University of Arizona, Marino Protti of Universidad Nacional de Costa Rica, and Jaime A. Campos of the University of Chile say the data have led to "new ideas about the spectrum of the physical processes involved in seismic rupture, geometry of subduction, triggered [seismic] events, nonvolcanic tremors and the earthquake cycle."

Several of the papers in the section discuss past major earthquakes in Mexico and Chile, with an eye to characterizing the properties in each event that may help explain earthquake cycles and calculate future seismic hazards in the region. In their paper about the magnitude 8.8 Maule earthquake in 2010 and the magnitude 8.3 Illapel earthquake in 2015, for instance, Leonardo Aquirre and colleagues at the University of Concepcion discuss how satellite observations of crust deformation can be used to build a model of crust movement related to motion along a subducting slab during different parts of the earthquake cycle for central Chile. Analysis of the 2014 magnitude 7.3 Papanoa earthquake by Pouye Yazdi of the Universidad Politécnica de Madrid in Spain could offer valuable data to inform seismic hazard estimates in the part of the central part of the Mexican subduction zone.

Tsunamis are part of the subduction zone's past and probable near future, and understanding the possible scenarios to generate tsunamis at this interface is important for safety planning and economic mitigation, write Mauricio Fuentes Serrano of the University of Chile and colleagues. Probability maps created from these scenarios suggest that northern Chile has a significant tsunami hazard, the researchers conclude.

Two papers take a closer look at tectonic phenomena at some of the complex plate boundaries in the zone, including an analysis of tectonic tremor along the converging boundary between the Nazca and South American plates and the Nazca, South American and Antarctic plates. Increasingly, these observations are made with the help of ocean-bottom seismometers.

Other papers in the section examine subduction zone structure where the Rivera oceanic plate dives beneath the North American plate in Mexico's Jalisco Block and south of María Cleofas Island, as well as the complex structures below southern Peru associated with the subducting Nazca plate.

Seismological Society of America

Related Subduction Zone Articles from Brightsurf:

The connectivity of multicomponent fluids in subduction zones
A team of researchers has discovered more about the grain-scale fluid connectivity beneath the earth's surface, shedding new light on fluid circulation and seismic velocity anomalies in subduction zones.

Distinct slab interfaces found within mantle transition zone
Prof. CHEN Qifu's group from the Institute of Geology and Geophysics, Chinese Academy of Sciences (IGGCAS) and their collaborators observed two distinct seismic discontinuities within the mantle transition zone (~410 km to 660 km) beneath the western Pacific.

New fault zone measurements could help us to understand subduction earthquake
University of Tsukuba researchers have conducted detailed structural analyses of a fault zone in central Japan to identify the specific conditions that lead to devastating earthquake.

A review of ridge subduction, magmatism and metallogenesis
Ridge subduction events are very common and important geodynamic processes in modern oceanic plate tectonics (Figure 1), and play an important role in the generation of arc magmatism, material recycling, growth and evolution of continental crust, deformation and modification of overlying plates and metallogenesis.

Is the Earth's transition zone deforming like the upper mantle?
In a recently published paper in Earth and Planetary Science Letters, researchers from the Geodynamics Research Center, Ehime University and the University of Lille combine numerical modeling of dislocation glide and results from diffusion experiments to revisit the rheology of wadsleyite, ringwoodite and majorite garnet under geological strain rates across the transition zone of the Earth's mantle based on theoretical plasticity modeling.

Scientists review the metallogenesis and challenges of porphyry copper systems above subduction zone
Porphyry copper ± molybdenum ± gold deposits (PCDs) are the most economically important magmatic-hydrothermal metallogenic system above subduction zones, which have supplied nearly 3/4 of the world's copper, 1/2 of the molybdenum and 1/5 of the gold, as well as large amounts of silver, zinc, tin and tungsten, with however their metallogenesis remaining controversial.

Does accelerated subduction precede great earthquakes?
A strange reversal of ground motion preceded two of the largest earthquakes in history.

Badger behavior inside the cull zone
A study led by researchers at international conservation charity ZSL (Zoological Society of London) and Imperial College London has found that culling drives badgers to roam 61% further afield -- helping to explain why the practice, intended to reduce bovine TB transmission, can sometimes exacerbate the problem instead

A Goldilocks zone for planet size
Harvard University researchers described a new, lower size limit for planets to maintain surface liquid water for long periods of time, extending the so-called Habitable or 'Goldilocks'' Zone for small, low-gravity planets.

Water detected on an exoplanet located in its star's habitable zone
An international study lead by UdeM astronomer Björn Benneke has detected water vapor on the planet K2-18b; this represents a major discovery in the search of alien life.

Read More: Subduction Zone News and Subduction Zone Current Events is a participant in the Amazon Services LLC Associates Program, an affiliate advertising program designed to provide a means for sites to earn advertising fees by advertising and linking to