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Seismology

All articles tagged with #seismology

Hidden mantle blobs could rewrite Earth's tectonic story
science5 days ago

Hidden mantle blobs could rewrite Earth's tectonic story

Seismologists using high-resolution full-waveform inversion on earthquake data detected large, anomalous pockets in the lower mantle beneath the Pacific, visible as regions where seismic waves move unusually fast or slow. These “sunken worlds” may be remnants of ancient plates or other mantle materials, challenging traditional ideas about subduction and plate evolution. A ETH Zurich–Caltech team notes the exact composition is unclear and more data and methods (including EM signals and mineral physics) are needed, but the findings could require updates to models of mantle convection and heat transfer. The study appears in Scientific Reports.

via Earth.com|
#full-waveform-inversion#geophysics#mantle
Deep-Earth Quakes Detected Across Continents, Redefining Earth's Interior
science10 days ago

Deep-Earth Quakes Detected Across Continents, Redefining Earth's Interior

A new global study maps mantle earthquakes—deep quakes originating below the Moho—and shows they occur worldwide, not just in special regions. These deep quakes can be found from the Alps to the Himalayas, East Africa, the western United States, and even the Bering Sea, suggesting mantle earthquakes are more widespread than previously thought. The researchers used a wave-analysis method to distinguish crust-origin quakes from mantle ones and focused on non-subduction regions, highlighting potential links to continental collision and rifting; most mantle quakes are too deep to be felt at the surface (depths around 35 km or more).

via Live Science|
#continental-tectonics#global-map#mantle-earthquakes
Moon Faces a 4% Chance of a 60-Meter Asteroid Hit in 2032
space25 days ago

Moon Faces a 4% Chance of a 60-Meter Asteroid Hit in 2032

A ~60-meter asteroid named 2024 YR4 could strike the Moon on December 22, 2032, with about a 4% probability, potentially creating a 1-kilometer crater and a moonquake of magnitude 5.0–5.1, offering a rare scientific 'natural experiment' as observers track optical, thermal, and seismic signals—while fallout debris could reach Earth and affect satellites.

via Indian Defence Review|
#arxiv#asteroid-2024-yr4#lunar-impact
Seismic Signals Map Space Debris Path in Real Time
science26 days ago

Seismic Signals Map Space Debris Path in Real Time

Researchers show that existing earthquake seismometers can detect shock waves from reentering space debris, enabling near real-time tracking of its path and potential landing sites; using 127 seismometers across southern California to map China's Shenzhou-15 module's descent (Mach 25–30) they estimated speed, altitude, and breakup points—information that can complement radar predictions and speed debris recovery to reduce hazards.

via SciTechDaily|
#reentry#science#seismology
Five-Block Boundary at Mendocino Triple Junction Rewrites Quake Forecasts
science29 days ago

Five-Block Boundary at Mendocino Triple Junction Rewrites Quake Forecasts

A new analysis of tiny, low-frequency earthquakes around the Mendocino triple junction shows the boundary is made up of five moving blocks rather than three plates, with shallower subduction than previously thought, prompting updates to earthquake hazard models and potentially improving predictions for major quakes along California and Cascadia.

via ScienceAlert|
#low-frequency-quakes#mendocino-triple-junction#plate-tectonics
Tiny Quakes Reveal a Hidden Five-Piece Subduction Puzzle Under Northern California
science1 month ago

Tiny Quakes Reveal a Hidden Five-Piece Subduction Puzzle Under Northern California

Scientists using a dense array of seismometers tracked tiny, often imperceptible earthquakes to map five moving tectonic pieces beneath Northern California, including hidden fragments of the North American and Pioneer/Farallon blocks. The study refines the subduction-zone model around the Mendocino Triple Junction, explains a shallower-than-expected 1992 earthquake, and has implications for seismic hazard assessment along the Cascadia and San Andreas regions.

via SciTechDaily|
#cascadia-subduction-zone#low-frequency-earthquakes#mendocino-triple-junction
Cracking the Seismic Code: Parkfield's Forecast and the Quest for a Crystal Ball
planet-earth1 month ago

Cracking the Seismic Code: Parkfield's Forecast and the Quest for a Crystal Ball

The piece examines why predicting earthquakes is so challenging, using California’s Parkfield Experiment on the San Andreas Fault as a focal point. Although scientists predicted a quake between 1985 and 1993, a magnitude-6.0 event occurred in 2004—11 years later—highlighting the inherent uncertainty of fault behavior. The article explains how fault geometry, subsurface properties, and limited historical data complicate forecasts, while noting advances in hazard maps, sensor networks, InSAR, GPS, and AI that improve risk assessment and move toward a practical (though not perfectly precise) seismic 'crystal ball.'

via Live Science|
#earthquake-prediction#parkfield-experiment#planet-earth
Scientists Discover Unusual Deep Structure Beneath Bermuda Triangle
science2 months ago

Scientists Discover Unusual Deep Structure Beneath Bermuda Triangle

Scientists have discovered a thick layer of low-density rock beneath Bermuda, which may explain the island's unusual buoyancy and the persistent swell supporting it, despite the absence of recent volcanic activity or a mantle plume. This underplating could be a remnant of volcanic activity from 30-35 million years ago, helping Bermuda stay above water until sea levels rise further.

via ScienceAlert|
#bermuda#geology#mantle-layer