New clues to deep earthquake mystery
Deep earthquakes can provide vital clues to understanding plate tectonics and the Earth's interior. A new model simulates subduction zones, showing that deformation is a major factor in deep earthquakes.
Subduction
Articles tagged with Subduction
Does accelerated subduction precede great earthquakes?
Researchers found large-scale wobbling in the Earth's surface near plate boundaries before massive Chile and Japan quakes. The study suggests that periods of enhanced tugging may accelerate the inevitable failure at shallower segments of the subduction zone, leading to great earthquakes.
'Wobble' may precede some great earthquakes, study shows
Researchers found a 'wobble' in Japan's landmasses before the 2011 magnitude-9 earthquake that killed over 15,500 people. The movement, detected by GPS data, may indicate future large subduction-zone earthquakes. However, the study's findings cannot be applied to other subduction zones without comparable data.
Sediments may control location, magnitude of megaquakes
Researchers found that variations in subducting sediments can influence the magnitude and location of megathrust earthquakes. Sediment thinning caused by volcanic activity may play a key role in determining the size and distribution of these catastrophic events.
Eclectic rocks influence earthquake types
Research from a global team of scientists found that diverse rock types at New Zealand's largest fault contribute to varying earthquake types. Slow slip events and tsunami-generating tremors are linked to the unique properties of each rock type.
Scientists get first look at cause of 'slow motion' earthquakes
An international team of scientists has identified the conditions that lead to slow motion earthquakes by drilling down to 1km deep in water depths off New Zealand. The study revealed a unique mix of different rock types and topography that causes slow slip events, which can trigger larger earthquakes and tsunamis.
Shifts in deep geologic structure may have magnified great 2011 Japan tsunami
Researchers found that the angle at which the ocean plate dives under the continental plate may have gradually shallowed out over millions of years, leading to the formation of an extensional fault that could have magnified the tsunami. The study used computer models and various data sets to support its findings.
Sinking sea mountains make and muffle earthquakes
A new study found that underwater mountains pulled into subduction zones can set the stage for powerful quakes and create conditions that end up dampening them. Researchers used a computer model to simulate the effects of seamounts on surrounding rock and sediment, finding that the brittle rock ahead of the seamount creates powerful ea...
Deformation of Zealandia, Earth's Hidden continent, linked to forging of the Ring of Fire
A new study published in Geology proposes that Zealandia's topographic upheaval may be linked to the formation of the western Pacific's infamous Ring of Fire. Fossils from recent seafloor drilling indicate dramatic elevation changes between 50-35 million years ago, coinciding with a global reorganization of tectonic plates.
Upper-plate earthquakes caused uplift along New Zealand's Northern Hikurangi Margin
Researchers found that upper-plate earthquakes, not subduction earthquakes, caused coastal uplift along New Zealand's Northern Hikurangi Margin. Marine terraces at two sites showed different uplift patterns, leading to the mapping of new offshore faults that may contribute to these earthquakes.
SourceSeismological Society of America·JournalBulletin of the Seismological Society of America·DateJan 28, 2020
3-D models of cascadia megathrust events match coastal changes from 1700 earthquake
Researchers used 3D models of Cascadia megathrust events and geological evidence to recreate the 1700 earthquake's impact on the Pacific Northwest coast. The study suggests that a rupture extending just offshore could cause coastal subsidence, with an estimated magnitude between 8.7 and 9.2.
SourceSeismological Society of America·JournalBulletin of the Seismological Society of America·DateOct 29, 2019
'Treasure trove' of quake clues could be unearthed by wavy new technique
Researchers have developed a new method to study rocks along fault lines, revealing clearer views of the Earth's crust. This technique combines acoustic mapping with full waveform inversion, enabling scientists to better understand why earthquakes and tsunamis occur.
SRL publishes focus section on Subduction Zone processes in the Americas
Researchers analyzed past major earthquakes in Mexico and Chile to understand earthquake cycles and calculate future seismic hazards. The data also helped develop new ideas about the physical processes involved in seismic rupture, geometry of subduction, and tsunami generation in the region.
What drives plate tectonics?
Researchers found 'switches' between continental rupture, collision, and oceanic subduction initiation in the Tethyan evolution. Oceanic slabs drove continental fragments into their final positions, controlling supercontinent assembly and breakup cycles.
How to interact between mantle and crustal components in the subduction zone?
This study reveals complex deformation and metamorphism processes, melt/fluid interactions with crust-mantle rocks, and material circulation in subduction zones. Crust-mantle physical interactions control geometry, tectonic associations, and chemical interaction in orogen and mantle wedge.
Microbes may act as gatekeepers of Earth's deep carbon
A groundbreaking study reveals that microbes in subduction zones consume and trap carbon, reducing its availability on Earth's surface. This process has significant implications for understanding Earth's fundamental processes and the potential to mitigate climate change.
Study: Microbes could influence Earth's geological processes as much as volcanoes
Researchers found that microbes consume and trap carbon sinking into the trench off Costa Rica's Pacific coast, potentially influencing geological processes on similar scales as volcanoes. This discovery has important implications for understanding carbon movement from Earth's surface into its interior over geological timescales.
The solid Earth breathes
Researchers developed a new method to investigate tectonic C cycling in the complex Sunda margin, finding that only a fraction of sedimentary carbon returns to the Earth, contributing to atmospheric CO2. This discovery has significant implications for understanding the solid Earth's role in regulating global climate.
Tide gauges capture tremor episodes in Cascadian subduction zone
Researchers used hourly water level records from tide gauges to detect episodic tremor and slip patterns in the Cascadia Subduction Zone. The study found that these events occurred every 14.6 months between 1996 and 2011, but not during the pre-GPS era, suggesting a potential change in the pattern over time.
SourceSeismological Society of America·JournalBulletin of the Seismological Society of America·DateFeb 15, 2019
Scientists reconstruct ancient lost plates under Andes mountains
Researchers have reconstructed ancient lost plates under the Andes mountains, offering a glimpse of the Earth's surface millions of years ago. The study reveals that the formation of the mountain range was more complex than previously thought, with evidence of volcanic activity and plate tectonics.
'Silent slip' along fault line serves as prelude to big earthquakes, research suggests
A study at Oregon State University found that 'silent slip' - a brief episode of shallow mantle creep and seismic swarms - occurs before large earthquakes. The research deployed seismometers on the ocean bottom to detect over 1,600 earthquakes at the Blanco Ridge fault.
Machine learning-detected signal predicts time to earthquake
Researchers applied machine learning to analyze Cascadia data, discovering a constant tremor that predicts slow slippage and fault failure. The study found a direct parallel between the loudness of the signal and the physical changes, allowing for more accurate predictions of megaquakes.
Seismic study reveals huge amount of water dragged into Earth's interior
A seismic study spanning the Mariana Trench reveals that subduction zones drag about three times more water into the deep Earth than previously estimated. The observations highlight the important role of subduction zones in the global water cycle, with implications for our understanding of the Earth's interior.
New study reveals connection between climate, life and the movement of continents
A new study by University of Texas at Austin researchers links sediment movement to continental drift speed, suggesting a key role for feedback mechanisms. The findings challenge existing ideas on plate interaction and may explain variations in plate speeds, such as India's rapid northward acceleration.
Seismic study reveals huge amount of water dragged into Earth's interior
A new seismic study reveals that subduction zones drag about three times more water down into the deep Earth than previously estimated. The observations from the Mariana Trench have important implications for the global water cycle, suggesting that much of the Earth's water is being recycled through volcanic activity.
Rice U. scientists uncover relationship between tremors, water at the Cascadia margin
Researchers at Rice University have discovered a link between tiny tremors on the Cascadia margin and fluid activity deep within the Earth's crust. The study reveals that these small quakes are related to slippage in the subducting plate, which releases fluids into sediments trapped beneath the overriding plate.
Mexico's 2017 Tehuantepec quake suggests a new worry
Researchers found a deep, rupturing subduction zone earthquake that defies existing models, indicating the need for reevaluation of hazard maps and building codes. The study suggests seawater infiltration may have accelerated cooling in the Cocos plate, making it susceptible to tension earthquakes.
Upper Cretaceous trench deposits of the Neo-Tethyan subduction zone
The Jiachala Formation, a key deposit in the Neo-Tethyan subduction zone, was formed in a submarine fan environment during Late Cretaceous (~88-84 Ma) at the active southern margin of the Asian plate. Provenance analysis indicates it originated from the Gangdese arc and central Lhasa terrane.
Pieces of mantle found rising under north and south ends of Cascadia fault
Scientists have discovered regions with lower seismic wave velocities beneath both ends of the Cascadia fault zone, indicating rising pieces of the Earth's upper mantle. These anomalies could modulate plate coupling forces and influence the location, frequency, and strength of earthquake events.
New insight into Earth's crust, mantle and outer core interactions
Researchers confirm connection between plate tectonics, mantle flow and magnetic field reversals, suggesting a 120-130 million year delay. This finding provides new insights into the interaction between Earth's crust, mantle and core.
Basin growth strata and its structural control in the region of Zhangjiakou, North Hebei, China
Researchers identify five types of growth strata developed in different structures, suggesting a 'pair' of basement-involved fold-thrust belt and flexure basin controlled by flat subduction. Sediments record the history of the Yanshanian Movement and provide key evidence for tectonic property of Northeast continental margin.
UMass Amherst geoscientist will study earthquake zones around the world
Haiying Gao will study five subduction zones across the globe to characterize differences and similarities in large earthquakes. Her advanced modeling techniques will rely on sensor data from land-based and deep-ocean seismic stations.
Eyewitness accounts fill in details of 1946 Dominican Republic tsunami
Researchers used eyewitness accounts from 2014 and 2016 to reconstruct the 1946 tsunami's heights and distances, challenging previous estimates. The study found tsunami heights over five meters and flooded areas of up to 600 meters inland.
Subduction of the Pacific plate resulted in the destruction of the North China Craton
The subduction of the Pacific plate resulted in the thinning and replacement of the lithospheric mantle in the North China Craton. The Yanshan Movement, a decratonization process, was characterized by lithospheric thinning and crustal detachment triggered by asthenospheric upwelling.
Garnet reveals source of water to fuel powerful volcanoes and earthquakes
Research shows that water-bearing minerals release water underneath geologic hot spots, lubricating earthquakes and fueling volcanoes. A new spectroscopy technique applied to garnet containing fragments of quartz reveals the source of water, contradicting conventional thermodynamic equations.
Mexico's 2017 earthquake emerged from a growing risk zone
Researchers identified a bending fault line in the Pacific Ocean as the likely cause of the 7.1 magnitude Puebla earthquake, which caused significant damage in Mexico City. The study suggests that earthquakes like this one may be more common than previously thought in a region southeast of Mexico City.
Deep-sea observatories to offer new view of seabed earthquakes
A mission is underway to lower sub-seafloor observatories into the Hikurangi subduction zone off New Zealand. This expedition aims to understand why destructive tsunamis occur after shallow earthquakes and underwater landslides, shedding light on New Zealand's largest earthquake and tsunami hazard.
Researchers embark on first-ever slow earthquake drilling mission
A team of scientists, led by Penn State's Demian Saffer and Laura Wallace, is installing observatories beneath the sea floor to study slow earthquakes. They aim to uncover links between slow earthquakes, large normal earthquakes, and tsunami generation risk.
Acoustic imaging reveals hidden features of megathrust fault off Costa Rica
Researchers have obtained detailed three-dimensional images of a megathrust fault west of Costa Rica, revealing long grooves and other features that may control how the fault slips in an earthquake. The study provides unprecedented insight into the mechanisms at work along these faults, critical for disaster management worldwide.
September 2017 earthquakes highlight successes of Mexico's early warning system
The September 2017 earthquakes showcased the effectiveness of Mexico's SASMEX early warning system, which detected the magnitude 8.2 Tehuantepec earthquake and sent alerts to residents with almost two minutes' notice. However, improvements are needed to reduce processing times and ensure timely warnings for all residents.
Residual strain despite mega earthquake
Researchers from GEOMAR and Universidad de Chile found that the 2016 earthquake released accumulated energy from a previous quake in 1960, with a slip of over 4.5 meters. This study suggests reevaluating seismic cycles for risk assessment and construction recommendations
SourceHelmholtz Centre for Ocean Research Kiel (GEOMAR)·JournalGeophysical Journal International·DateDec 13, 2017
The origin of the Andes unraveled
The Andes were formed due to the South American subduction zone, where an oceanic plate sinks into the Earth's mantle, causing crustal shortening and mountain building. The subduction zone's size and depth led to large-scale flow in the deep mantle, resulting in the continent's westward drag and collision with the subduction zone.
Seafloor sediments appear to enhance Earthquake and Tsunami danger in Pacific Northwest
A study by University of Texas at Austin researchers found that compact sediments along the Cascadia Subduction Zone increase earthquake and tsunami hazards. Compact sediments offshore of Washington and northern Oregon can lead to more stress buildup and longer rupture distances, making them prone to triggering larger tsunamis.
Clay mineral waters Earth's mantle from the inside
High-pressure X-ray measurements reveal the formation of a new phase of kaolinite, a clay mineral containing aluminium, under conditions similar to those in subduction zones. The super-hydrated phase contains more water than any other known aluminosilicate mineral in the mantle.
Researchers create largest, longest multiphysics earthquake simulation to date
A team of researchers from LMU and TUM used supercomputing resources to simulate a massive earthquake with 1,500km of non-linear fracture mechanics, achieving a 13-fold improvement in time to solution. The simulation helped understand the complex process behind megathrust earthquakes, which can unleash violent tsunamis.
Japanese earthquake zone strongly influenced by the effects of friction
Researchers at Kyushu University have identified a strong influence of pre-existing faults on earthquake location and behavior in the Nankai Trough offshore Japan. The study found that aftershocks only occurred in front of an ancient accretionary prism, where stress accumulation is greatest.
Siletzia's origin along an oceanic spreading center: What's Bremerton got to do with it?
High-precision age dates reveal that Siletzia was built near Bremerton and its collision with North America led to a jammed subduction zone, causing tectonic ripple effects. The study provides new insights into the Pacific Northwest's evolution.
Fifty simulations of the 'Really Big One' show how a 9.0 Cascadia earthquake could play out
Researchers simulated 50 scenarios of a magnitude-9.0 Cascadia earthquake, finding that coastal areas would be hardest hit and locations in sediment-filled basins like Seattle would shake more. The intensity of shaking can vary by a factor of 10 depending on the scenario.
Measuring a crucial mineral in the mantle
Researchers used instrumented nanoindentation to measure olivine's strength, finding it weaker with larger diamond tips. The study resolves a long-standing debate on the mineral's strength and has implications for understanding plate tectonics and volcanic activity.
Earthquake triggers 'slow motion' quakes in New Zealand
Scientists have documented a clear-cut instance of a massive earthquake triggering slow slip events in New Zealand, some occurring as far away as 300 miles from the epicenter. This study provides new insights into the relationships between slow slip events and earthquakes.
Scientists embark on expedition to submerged continent Zealandia
Researchers will drill into the seafloor of Zealandia, examining a shift in plate movement that occurred 50 million years ago. The expedition aims to understand the timing and causes of this change, which led to the development of new volcanoes and changes in ocean circulation patterns.
Crustal limestone platforms feed carbon to many of Earth's arc volcanoes
A global data set reveals that volcanic arcs mobilize carbon from crustal carbonate platforms, particularly in Italy and Indonesia. This finding requires a downward revision of past organic carbon burial estimates.
Slow earthquakes occur continuously in the Alaska-Aleutian subduction zone
Researchers found near-continuous tremor activity and 1,300 low-frequency earthquakes in the region, suggesting a connection to damaging earthquakes. The study used a novel 'beam back projection' method to track slow earthquakes minute-by-minute, revealing clusters of tremor sources with distinct properties.
Japanese slow earthquakes could shed light on tsunami generation
Researchers found that 50% of energy is released in slow earthquakes, reducing tsunami risk, but the exact mechanism remains unclear. The study used data from instruments placed on the seafloor and in boreholes east of Japan's coast to understand slow-slip earthquakes and their impact on large earthquakes and tsunamis.
Slow earthquakes in ocean subduction zones shed light on tsunami risk
Researchers studying slow-slip earthquakes on the seafloor off Japan's coast have gained new insights into undersea earthquakes and tsunami creation. About 50% of energy released during these events can be dissipated, potentially reducing tsunami risk.
Sediment from Himalayas may have made 2004 Indian Ocean earthquake more severe
Research published in Science journal found that sediment warming contributed to the severity of the 2004 Sumatra earthquake and tsunami, killing over 250,000 people. The study suggests a similar mechanism could be at play in other subduction zones worldwide.
Researchers drill deep to understand why the Sumatra earthquake was so severe
A team of scientists found that dehydration of minerals deep below the ocean floor influenced the severity of the 2004 Sumatra earthquake. The researchers used ocean drilling samples to understand the process and its potential impact on other subduction zones.
The initial collision between Indian and Asian continental
Researchers propose a new model for the initial India-Eurasia continental collision, which led to the formation of the Tibetan Plateau. The model suggests an earlier collision timing between 65 Ma and 63 Ma, resulting in large-scale continental subduction and deformation across central Asia.
Volcanic arcs form by deep melting of rock mixtures
Researchers discovered a previously unknown process involving the melting of intensely-mixed metamorphic rocks, known as mélange rocks, that form through high stress during subduction. This finding changes our understanding of how volcanic arc lavas are formed and may have implications for earthquake studies and volcanic eruption risks.
Cold plates and hot melts
A global scientific team has uncovered significant information about the early stages of subduction in the Pacific Ring of Fire. Analysis of a drill core from 2014 provides evidence that volcanism began around 30-40 million years ago, with explosive stratovolcanoes forming later.
SourceHelmholtz Centre for Ocean Research Kiel (GEOMAR)·JournalEarth and Planetary Science Letters·DateFeb 10, 2017