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Quake (natural phenomenon)
Quake (natural phenomenon)
Quake (natural phenomenon)
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A quake is the result when the surface of a planet, moon or star begins to shake, usually as the consequence of a sudden release of energy transmitted as seismic waves, and potentially with great violence. The types of quakes include earthquake, moonquake, marsquake, venusquake, sunquake, starquake, and mercuryquake. They can also all be referred to generically as earthquakes.

Earthquake

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Main article: Earthquake

An earthquake is a phenomenon that results from the sudden release of stored energy in the Earth's crust that creates seismic waves. At the Earth's surface, earthquakes may manifest themselves by a shaking or displacement of the ground and sometimes cause tsunamis, which may lead to loss of life and destruction of property. An earthquake is caused by tectonic plates (sections of the Earth's crust) getting stuck and putting a strain on the ground. The strain becomes so great that rocks give way and fault lines occur.

Moonquake

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"Moonquake" redirects here. For other uses, see Moonquake (disambiguation).
Further information: Lunar seismology

A moonquake is the lunar equivalent of an earthquake (i.e., a quake on the Moon) although moonquakes are caused in different ways. They were first discovered by the Apollo astronauts. The largest moonquakes are much weaker than the largest earthquakes, though their shaking can last for up to an hour, due to fewer attenuating factors to damp seismic vibrations.[1]

Information about moonquakes comes from seismometers placed on the Moon from 1969 through 1972. The instruments placed by the Apollo 12, 14, 15 and 16 missions functioned perfectly until they were switched off in 1977.

There are at least four kinds of moonquake:

  • Deep moonquakes (~700 km below the surface, probably tidal in origin)[2][3][4]
  • Meteorite impact vibrations
  • Thermal moonquakes (the frigid lunar crust expands when sunlight returns after the two-week lunar night)[5]
  • Shallow moonquakes (50–220 kilometers below the surface)[6]

The first three kinds of moonquakes mentioned above tend to be mild; however, shallow moonquakes can register up to mB=5.5 on the body-wave magnitude scale.[7] Between 1972 and 1977, 28 shallow moonquakes were observed. Deep moonquakes tend to occur within isolated kilometer-scale patches, sometimes referred to as nests or clusters.[8]

Marsquake

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Main article: Marsquake

A marsquake is a quake that occurs on the planet Mars. A 2012 study suggests that marsquakes may occur every million years.[9] This suggestion is related to evidence found then of Mars's tectonic boundaries.[10] NASA's InSight lander, which was active between early 2019 and late 2022, recorded over 1,300 individual seismic events. Of these, many were marsquakes resembled terrestrial earthquakes, and several events were confirmed to be meteorite impacts.[11][contradictory]

Venusquake

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A venusquake is a quake that occurs on the planet Venus.

A venusquake may have caused a new scarp and a landslide to form. An image of the landslides was taken in November 1990 during the first flight around Venus by the Magellan spacecraft. Another image was taken on July 23, 1991 as the Magellan revolved around Venus for the second time. Each image was 24 kilometres (15 mi) across and 38 kilometres (24 mi) long, and was centered at 2° south latitude and 74° east longitude. The pair of Magellan images shows a region in Aphrodite Terra, within a steeply sloping valley that is cut by many fractures (faults).[12]

Sunquake

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Main articles: Helioseismology and Moreton wave

A sunquake is a quake that occurs on the Sun.

Seismic waves produced by sunquakes occur in the photosphere and can travel at velocities of 35,000 kilometres per hour (22,000 mph) for distances up to 400,000 kilometres (250,000 mi) before fading away.[13]

On July 9, 1996, a sunquake was produced by an X2.6 class solar flare and its corresponding coronal mass ejection. According to researchers who reported the event in Nature, this sunquake was comparable to an earthquake of a magnitude 11.3 on the Richter scale. That represents a release of energy approximately 40,000 times greater than that of the devastating 1906 San Francisco earthquake, and far greater than that of any earthquake ever recorded. Such an event contains the energy of 100–110 billion tons of TNT or 2 million modest sized nuclear bombs. It is unclear how such a relatively modest flare could have liberated sufficient energy to generate such powerful seismic waves.[13][14]

The ESA and NASA spacecraft SOHO records sunquakes as part of its mission to study the Sun.

Starquake

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"Starquake" redirects here. For other uses, see Starquake (novel) and Starquake (video game).
See also: Asteroseismology

A starquake is an astrophysical phenomenon that occurs when the crust of a neutron star undergoes a sudden adjustment, analogous to an earthquake on Earth.[15] Starquakes are thought to result from two different mechanisms. One is the huge stresses exerted on the surface of the neutron star produced by twists in the ultra-strong interior magnetic fields. A second cause is a result of spindown. As the neutron star loses linear velocity due to frame-dragging and by the bleeding off of energy due to it being a rotating magnetic dipole, the crust develops an enormous amount of stress. Once that exceeds a certain level, it adjusts itself to a shape closer to non-rotating equilibrium: a perfect sphere. The actual change is believed to be on the order of micrometers or less, and occurs in less than a millionth of a second.

The largest recorded starquake was detected on December 27, 2004 from the ultracompact stellar corpse SGR 1806-20.[16] The quake, which occurred 50,000 light years from Earth, released gamma rays equivalent to 1037 kW. Had it occurred within a distance of 10 light years from Earth, the quake could have triggered a mass extinction.[17]

Mercuryquake

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A mercuryquake is a quake that occurs on Mercury. In 2016 it has been suggested that quakes might happen on Mercury due to the planet's contraction as the interior cools, impact vibrations or from heat or possibly magma rising from the core and mantle. It has not been measured or proven yet due to the fact that no probes have landed on its surface.

See also

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References

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Revisions and contributorsEdit on WikipediaRead on Wikipedia

Quake (natural phenomenon)

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from Grokipedia
A quake is the sudden shaking of the surface or interior of a , , or star resulting from the abrupt release of , which generates seismic waves that propagate through the body. On , this phenomenon is known as an , often simply called a quake, and is the result of energy release in the 's causing ground motion. Quakes also occur on other celestial bodies, such as moonquakes on the and marsquakes on Mars, detected through space missions. This phenomenon originates from the sudden slip along a fault, a in the body's crust or surface where blocks of material move past one another due to accumulated stress. Earthquakes primarily occur due to the movement of tectonic plates, large rigid sections of the Earth's outer shell that float on the semi-fluid beneath them and interact at plate boundaries. These plates move slowly—typically a few centimeters per year—but become locked by friction at their edges, building up elastic strain until the stress overcomes the friction, causing a sudden slip and the release of seismic energy. Most quakes happen along plate boundaries, such as the in , where the Pacific Plate slides northwestward past the North American Plate at about 2 inches per year, though intraplate earthquakes can also occur within tectonic plates due to internal stresses. Faults are classified by their movement, including normal faults (where the hanging wall drops relative to the footwall), reverse faults (where the hanging wall is pushed up), and strike-slip faults (horizontal sliding), each contributing to different patterns of ground displacement. The effects of earthquakes vary widely based on magnitude, depth, local , and distance from the —the point on the surface directly above the , or rupture origin. Primary hazards include intense ground shaking from seismic waves like compressional P-waves and shear S-waves, which can damage buildings by vibrating them at resonant frequencies, and surface faulting, where the ground ruptures along the fault line with displacements from inches to over 20 feet. In coastal areas, undersea quakes can trigger tsunamis, massive waves traveling at over 430 miles per hour in deep ocean and amplifying to heights of 80 feet near shore, leading to widespread inundation. Secondary hazards encompass , where saturated soil temporarily behaves like a liquid, causing buildings to sink or tilt (as seen in the 1964 Niigata earthquake), landslides and rockfalls on slopes, and lateral spreads that shift soil up to 150 feet, often exacerbating damage to infrastructure like bridges and pipelines. Earthquakes are measured using seismographs, which record ground motion as seismograms, allowing scientists to determine location via of P- and S-wave arrival times from at least three stations and magnitude based on the of seismic waves, reflecting the total energy released. Globally, thousands of quakes occur annually, but only a few dozen cause significant damage; the largest recorded, like the 1960 event (magnitude 9.5), highlight their potential for catastrophic impact, underscoring the importance of monitoring and preparedness in seismically active regions.

Introduction

Definition and Terminology

A quake, also known as a seismic event, is defined as the sudden release of stored elastic within a solid planetary body, which generates seismic waves that propagate through its interior. This process, often described by the , occurs when accumulated stress exceeds the frictional strength along a fault or fracture, leading to rupture and energy dissipation in the form of vibrations. The term "quake" applies broadly to such phenomena across celestial bodies with solid components, encompassing on , moonquakes on the , and similar events on other planets. Seismic quakes specifically refer to vibrations originating in the solid interiors of planetary bodies, distinguishing them from analogous events such as volcanic tremors, which involve continuous or spasmodic signals often linked to or gas movement, or in fluid environments like planetary atmospheres or oceans, where only compressional waves can propagate without shear components. Key terminology includes magnitude scales, which quantify the energy released; the (local magnitude, ML), originally developed for , measures the logarithm of the maximum amplitude of seismic waves recorded by seismographs, and has been adapted for other bodies like the where events are rated similarly up to around 5.5. The denotes the point on the body's surface directly above the (or focus), which is the subsurface location where the rupture initiates. Primary wave types are P-waves (primary or compressional waves), which alternately compress and dilate material parallel to their direction of travel and can propagate through solids, liquids, and gases, and S-waves (secondary or shear waves), which cause perpendicular motion and are restricted to solids. Quakes are generally classified by depth of the : shallow (0–70 km), intermediate (70–300 km), and deep (greater than 300 km), a categorization primarily established for but applicable analogously to other solid bodies where depth data is available. For example, shallow moonquakes on the occur at depths of 20–30 km and can reach magnitudes up to 5.5 on adapted Richter scales.

Historical Observations

Human observations of quakes date back thousands of years, with the earliest descriptive records appearing in ancient Chinese texts around 1177 B.C., describing seismic events that shook the ground and caused structural damage. These accounts, preserved in historical catalogs, often linked quakes to divine or natural omens, reflecting early attempts to document and interpret the phenomenon without scientific instruments. Subsequent records in regions like the Mediterranean and , such as those in biblical texts referencing an 8th-century B.C.E. event in , further illustrate growing awareness of quakes as recurring natural occurrences. One of the most devastating and well-documented historical earthquakes struck Shaanxi Province, , in 1556, claiming an estimated 830,000 lives and highlighting the scale of destruction possible from such events in densely populated areas. Advancements in the 19th and 20th centuries enabled systematic recording of earthquakes on . British geologist and seismologist John Milne invented the horizontal pendulum seismograph in 1880 while working in , a device that mechanically registered ground motion and laid the foundation for global seismic networks. This innovation allowed for the first instrumental detections of distant quakes, transforming anecdotal reports into quantifiable data. By the mid-20th century, expanded networks confirmed thousands of annual earthquakes worldwide, shifting focus from mere observation to analysis of patterns and precursors. Space exploration expanded quake observations beyond Earth starting in the late 20th century. During the Apollo missions from 1969 to 1972, astronauts deployed seismometers on the Moon's surface, detecting thousands of moonquakes, including deep events at depths of 700–1,200 kilometers below the surface and shallow ones triggered by thermal stresses. In the 1970s, NASA's lander on Mars provided the first seismic data from another , recording candidate events, including two likely marsquakes confirmed by 2023 reanalysis, and impacts that revealed insights into the Martian crust's structure. The ESA/ Solar and Heliospheric Observatory (SOHO), launched in 1995, captured the first observations of sunquakes in 1998, identifying helioseismic waves generated by solar flares that propagate through the Sun's interior like ripples on a pond. Recent missions have yielded direct detections of quakes on other worlds. NASA's lander, operational on Mars from 2018 to 2022, used a highly sensitive to record over 1,300 marsquakes, ranging from magnitude 0.7 to 4.7, providing the first clear evidence of ongoing tectonic activity on the Red Planet. These findings, analyzed through waveform modeling, confirmed Mars' active interior and helped refine models of planetary seismicity. As of 2025, the ESA/ mission, which completed its sixth and final Mercury flyby in January 2025 and is en route to orbital insertion in November 2026, continues to gather data on the planet's surface features suggestive of past tectonic activity, though direct seismic measurements await orbital insertion.

Causes and Mechanisms

Quakes driven by tectonic and stress-related mechanisms arise from the accumulation and sudden release of elastic strain energy within the crust of solid planetary bodies, primarily along pre-existing faults or fractures. The , proposed by Harry Fielding Reid following the , posits that gradual tectonic deformation builds up stress on either side of a fault until the frictional resistance is overcome, leading to abrupt slip and energy release as seismic waves. This process is analogous to stretching and snapping a , where the rocks behave elastically until the breaking point. The theory explains the periodic nature of quakes in tectonically active regions and has been validated through geodetic measurements showing crustal deformation rates matching long-term slip. The strain energy released during such slip can be approximated by the equation E=12μAd2E = \frac{1}{2} \mu A d^2, where μ\mu is the of the rock, AA is the area of the fault surface, and dd is the average slip distance. This formula captures the quadratic dependence of stored energy on displacement, highlighting how even modest slips over large fault areas can generate substantial seismic output. Not all stored energy is radiated as waves; a portion dissipates as heat and fracture energy, but the elastic rebound framework provides a foundational model for estimating quake potential across planetary interiors. On Earth, tectonic quakes are predominantly linked to plate tectonics, where the movement of lithospheric plates at boundaries generates internal stresses through subduction, rifting, and transform motion. Subduction zones, such as the Pacific Ring of Fire, produce compressional stresses as one plate overrides another, leading to thrust faults and megathrust quakes. Rifting at divergent boundaries, like the Mid-Atlantic Ridge, induces extensional stresses that activate normal faults, while transform boundaries, exemplified by the San Andreas Fault, accommodate shear stresses through strike-slip motion. These stress regimes—compressional, shear, and extensional—dictate fault types and quake characteristics, with shear stresses often dominating due to the brittle nature of the upper crust. Beyond , similar stress-related mechanisms operate on other bodies, though adapted to their unique geologies. For example, on the , tidal stresses contribute to deep moonquakes where ambient stresses combine with tidal shear to trigger slip along fault-like structures. On Mars, shallow quakes arise primarily from tectonic stresses due to planetary cooling and crustal contraction, with proposed modulating factors including tidal influences from Phobos and past groundwater pressures in a lacking active . In airless bodies like the and asteroids, regolith cracking from diurnal thermal stresses can generate shallow seismic events through repeated expansion and contraction along fractures. These processes underscore the universality of stress accumulation and rebound in driving quakes, scaled to each body's internal dynamics.

Gravitational and Thermal Causes

Gravitational forces play a significant role in triggering quakes on celestial bodies through tidal interactions between orbiting objects. For instance, in the -Moon system, tidal stresses induced by 's gravitational pull contribute to deep moonquakes, which occur at depths of 700–1,200 km and correlate with the lunar tidal cycle. These quakes, detected by Apollo seismometers, release energy equivalent to magnitude 2–5 events on and demonstrate how external gravitational perturbations can periodically destabilize internal structures. Similarly, —the Moon's apparent oscillation due to its elliptical orbit and —imposes additional periodic stresses on the lunar crust, contributing to shallow seismic activity by altering the orientation of tidal bulges and amplifying local strains up to several kilopascals. Thermal processes drive quakes through volumetric expansion and contraction in planetary materials, often resulting from uneven heating or cooling. On airless bodies like Mercury, while extreme diurnal temperature swings—ranging from about 100 at night to 700 during the day—cause regolith cracking via repeated expansion and contraction, the planet's primary seismic activity results from global thermal contraction and crustal shrinkage over billions of years, leading to tectonic faulting that generates mercuryquakes. These stresses arise from the planet's lack of atmosphere, causing rapid radiative heating and cooling that propagates cracks, with implications for surface stability. In stellar interiors, convective motions in the outer layers transport heat and excite global acoustic oscillations, known as helioseismic waves, which propagate through the plasma and reveal internal dynamics without fracturing solid structures. Thermal plumes at boundaries like Earth's core-mantle interface can contribute to long-term intraplate seismicity and volcanic activity over millions of years by altering lithospheric stresses through dynamic uplift, as evidenced by correlations with hotspot volcanism. The magnitude of such thermal stresses in crustal or mantle rocks is quantified by the relation σ=EαΔT\sigma = E \alpha \Delta T, where σ\sigma is the thermal stress, EE is Young's modulus (typically 50–100 GPa for silicates), α\alpha is the coefficient of thermal expansion (around 10−510^{-5} K−1^{-1}), and ΔT\Delta T is the temperature change; for ΔT≈100\Delta T \approx 100 K, this yields stresses of 50–100 MPa, sufficient to exceed rock strength in weakened zones. In , thermal interacts with to produce quake-like events, particularly through in sunspots, where tangled field lines snap and release energy, generating that ripple across the stellar surface as sunquakes. These events, observed during intense flares, involve reconnection sites in umbral regions of sunspots, propagating p-modes with frequencies of 3–4 mHz and amplitudes up to several m/s, distinct from routine convective oscillations.

Quakes in the Solar System

Seismic activity, or quakes, occurs across various bodies in the Solar System, driven by different mechanisms due to diverse geological and physical conditions. On , quakes are frequent and well-studied, primarily tectonic in origin. In contrast, other bodies lack active , leading to less frequent and lower-energy events from tidal forces, cooling, impacts, or . The table below summarizes key characteristics:
BodyPrimary CausesDetection MethodApproximate Frequency (per Earth year)Max Magnitude
Tectonic plate movementsGlobal seismograph networks~500,000 detectable9.5
MoonTidal, thermal, impacts, coolingApollo seismometers (1969-1977)Thousands (deep: 600-3,000)~5.8
MarsCrustal stresses, volcanic remnantsInSight SEIS (2018-2022)~300-350 detectable4.7
Volcanic, episodic tectonicsHypothetical; indirect evidence95-296 (Mw ≥4, estimated)Unknown
MercuryGlobal contraction, impactsInferred from imageryUp to ~100 (mag >3, estimated)Unknown

Earthquakes

Earthquakes, the most studied quakes, occur frequently on due to active , contrasting with sparser activity elsewhere. Annually, ~500,000 are detected globally, with ~81% along the . Tectonic events dominate (>90%), unlike induced or volcanic types on other bodies. Depths range from shallow (<70 km, most destructive) to deep (>300 km). Detection uses cooperative networks including the USGS's ~150-station Global Seismographic Network and thousands more worldwide for real-time location via P- and S-waves. Early warning systems, like (fully operational in as of mid-2025), provide seconds of advance notice.

Moonquakes

Moonquakes are seismic events occurring on the lunar surface and interior, distinct from earthquakes due to the Moon's lack of atmosphere and . The primary data on moonquakes come from the Apollo Passive Seismic Experiment (PSE), deployed between 1969 and 1977 across four sites (, 14, 15, and 16), which recorded thousands of events initially, with a 2024 reanalysis identifying over 22,000 lunar seismic events. These instruments, consisting of long- and short-period seismometers, captured vibrations from various sources, providing the foundational dataset for understanding lunar seismicity. Modern inferences, such as those from the (LRO), use imaging to map surface faults and infer ongoing stresses, though direct seismic detection awaits future missions. Moonquakes are classified into four main types based on depth, origin, and characteristics. Deep moonquakes occur at depths of 700–1,200 km, are the most numerous, and reach magnitudes up to about 2 on the , releasing low levels of energy. Shallow moonquakes, occurring at depths less than 200 km, are rare—with ~46 events identified in recent analyses—and can achieve magnitudes of 3.6 to 5.8, making them the most energetic natural lunar events, possibly linked to tectonic stresses. Thermal moonquakes are shallow, near-surface phenomena triggered by diurnal temperature fluctuations, with over 12,000 identified in data alone, though they are weak and low-magnitude. Meteoroid impacts generate seismic signals from surface collisions, with over 1,700 recorded events corresponding to impacts by objects of 100 g to 100 kg in . Deep moonquakes exhibit a frequency of between 600 and 3,000 events per year, clustered in over distinct "nests" primarily on the lunar nearside, and are strongly correlated with tidal forces from . These events show periodicity tied to the 13.6-day lunar perigee-apogee cycle and the longer 206-day nodal cycle, with increased activity when the Moon is closest to , amplifying tidal stresses. Shallow moonquakes and impacts occur less predictably, while thermal events align with the Moon's 27-day rotation and temperature extremes. Overall, the PSE data indicate that lunar is far less frequent and energetic than on , with total annual energy release estimated at less than 10¹⁵ ergs. The Moon's seismic activity reflects its rigid, seismically inactive , estimated to be about 1,000 km thick, which limits energy propagation and results in weak, high-frequency signals that attenuate quickly. Unlike , the Moon lacks active , so moonquakes arise from tidal deformations, , impacts, and internal cooling rather than or rifting. Evidence from LRO imagery reveals global contraction due to interior cooling, with the Moon's radius shrinking by approximately 100 meters over the past billion years, forming thrust faults that may contribute to shallow moonquakes and surface stresses. This contraction, combined with tidal influences, underscores the Moon's dynamic yet subdued geological state.

Marsquakes

Marsquakes are seismic events occurring on the surface of Mars, primarily detected through NASA's Interior Exploration using Seismometers () mission, which operated from November 2018 to December 2022. The lander's Seismic Experiment for Interior Structure (SEIS) instrument, a highly sensitive suite, recorded a total of 1,319 marsquakes during its operational period, providing the first direct evidence of seismic activity on the planet. SEIS was capable of detecting ground motions across a broad frequency range, from as low as 0.01 Hz up to 50 Hz, allowing it to capture both subtle and more intense vibrations. The largest recorded event, designated S1222a, occurred on May 4, 2022, with an estimated magnitude of 4.7, producing vibrations that lasted over six hours and originated approximately 3,700 kilometers from the lander. These marsquakes are categorized primarily by their frequency content into high-frequency (HF) events, which dominate the catalog and exhibit sharp onsets, and low-frequency (LF) events, which are rarer but longer-lasting. Depths of these events are generally shallow, with most hypocenters estimated at less than 40 km beneath the surface, concentrated in regions like the Cerberus Fossae system. Shallow crustal marsquakes (typically 1–30 km deep) may arise from localized stresses or residual volcanic activity, while deeper events (30–50 km) are linked to broader tectonic processes, such as crustal flexing induced by the massive volcanic bulge, in the absence of active on Mars. Seismic analysis indicates that Mars experiences approximately 300–350 detectable marsquakes per Martian year, though many are low-magnitude and short-duration, with significant events (above magnitude 3) occurring at a rate of roughly 50 per year. The observed seismic , which is notably low in the deep mantle, supports models of a partially liquid core, as higher attenuation would be expected in a fully solid interior. 2025 analyses confirmed a solid inner core and lumpy mantle with impact remnants. Marsquakes have profound implications for understanding the planet's internal structure and geological history. Variations in speeds, particularly slower S-wave velocities in the mid-crust (around 11–20 km depth), provide evidence for the presence of liquid water trapped in fractured rock layers, potentially representing remnants of ancient surface oceans that infiltrated the subsurface billions of years ago. In 2025, analyses integrating seismic data with orbital gravity measurements from missions like have further refined interior models, revealing kilometer-scale heterogeneities in the mantle and improving estimates of crustal thickness variations, including a solid inner core. These findings underscore Mars' ongoing geological activity and inform future explorations of its potential.

Venusquakes

Venusquakes refer to hypothetical seismic events on , driven primarily by volcanic resurfacing and potential tectonic processes beneath the planet's thick, high-pressure atmosphere. is thought to operate under a "stagnant " tectonic regime, where the rigid inhibits continuous plate motion, leading to episodic bursts of and localized deformation that could generate quakes. In this model, builds stress over time, occasionally relieved through rifting or plume-related activity, potentially producing venusquakes with moment magnitudes (Mw) of 4 or greater estimated at 95–296 events annually, even in a geologically subdued state. High-pressure conditions in the mantle may also facilitate limited plate-like behavior, contributing to irregular seismic activity tied to global resurfacing events. Indirect evidence for recent geological activity, which implies associated , comes from NASA's Magellan mission radar imaging in the early 1990s, revealing fresh lava flows and surface changes on volcanic structures like Sif Mons, indicating ongoing within the past few decades. For instance, an approximately 2.2-square-kilometer vent near Sif Mons showed morphological alterations between Magellan imaging passes, suggesting active extrusion that would likely produce seismic signals during emplacement. Earlier Soviet Venera landers, such as and 14 in 1982, deployed seismometers capable of detecting microseisms—minute vertical ground displacements on the order of 1 micron—but recorded ambiguous signals possibly attributable to wind or instrumental noise rather than confirmed tectonic events. Detecting venusquakes directly remains challenging due to Venus's extreme surface conditions, including temperatures around 464°C and pressures 92 times Earth's sea-level value, which limit lander longevity to hours and preclude dedicated deployments to date. Seismic waves on Venus are expected to exhibit higher frequencies owing to the hot, dry interior, which enhances wave propagation efficiency compared to Earth's water-saturated crust, potentially allowing global through with the dense CO₂ atmosphere. In this environment, quakes could generate detectable waves that propagate upward, but no such signals have been verified. Future missions offer prospects for indirect seismic insights; NASA's orbiter, launching no earlier than 2031, will map high-resolution topography and data to identify active geologic processes, including those linked to potential venusquakes, while constraining interior structure via measurements. Complementing this, the probe, also slated for the early , will descend through the atmosphere to sample gases and analyze surface composition, potentially revealing volcanic signatures tied to seismic-volcanic episodes. These efforts, alongside concepts for balloon-borne detectors, aim to probe quake-induced atmospheric perturbations without surface instruments.

Mercuryquakes

Mercuryquakes refer to inferred seismic events on Mercury, primarily driven by the planet's ongoing global contraction. Data from NASA's mission, which orbited Mercury from 2011 to 2015, revealed widespread thrust faults and lobate scarps—cliff-like landforms up to several kilometers high—indicating that the planet's radius has decreased by up to ~7 km overall since the formation of its oldest preserved crust, with evidence of ongoing contraction in recent geological time. These features suggest active tectonism, as small, previously undetected scarps imply slip events within the last few hundred thousand years, consistent with mercuryquake activity. The primary cause of mercuryquakes is the cooling and solidification of Mercury's iron-rich core, leading to volumetric contraction of the interior and compressive stresses in the that manifest as faulting. This global contraction forms the observed lobate scarps, with models estimating strain rates that could produce seismic events, though direct measurements are lacking due to the absence of a on past missions. Thermal and contraction from Mercury's extreme surface temperature swings (from -173°C to 427°C) may contribute minor stresses, but these are secondary to core cooling. Mercuryquakes are expected to be shallow, with focal depths likely less than 40 km, reflecting the planet's thin crust and brittle . Without an atmosphere to buffer impacts, collisions also generate seismic vibrations detectable as quake-like signals, similar to those on the airless ; small impacts occur frequently, adding to the planet's overall seismicity. Estimates of mercuryquake frequency vary by model, but contraction-driven events with magnitudes above 3 are projected at rates of up to 100 per decade during periods of peak activity, based on fault slip rates and accumulation. Tidal influences from Mercury's 3:2 spin-orbit could additionally trigger events up to magnitude 3.9 every 1-2 years. The ESA/ mission, which completed its sixth flyby in January 2025, is now scheduled for orbital insertion in November 2026 due to thruster issues, continuing to map tectonic features that refine these models, though no direct seismic detections have been reported to date.

Stellar Quakes

Sunquakes

Sunquakes refer to helioseismic oscillations on the Sun's surface, driven primarily by convective motions in the solar interior or impulsive energy releases from solar flares. Unlike seismic events on solid bodies, these are acoustic disturbances in the Sun's plasma, manifesting as global vibrations. The dominant modes are p-modes, which are pressure-supported sound waves trapped within the Sun, exhibiting periods between 3 and 10 minutes, with a typical value around 5 minutes. These oscillations arise from turbulent near the solar surface, continuously exciting millions of resonant modes that propagate as waves through the interior. Detection of sunquakes relies on high-precision measurements of the Sun's surface velocity via Doppler imaging. Instruments such as the Michelson Doppler Imager (MDI, operational 1995–2010) and the Helioseismic and Magnetic Imager (HMI, operational since 2010) aboard the (, launched in 1995) capture these surface ripples by resolving velocity shifts as small as 0.1 m/s, revealing expanding wave fronts from flare sites. Complementing space-based observations, the ground-based Global Oscillation Network Group (GONG) network of six telescopes provides near-continuous monitoring, with 2025 enhancements funded by the introducing next-generation designs for improved real-time data processing and forecasting capabilities. The primary impulsive causes of prominent sunquakes are solar flares, where sudden releases of magnetic energy excite acoustic modes, generating propagating wavefronts observable as surface ripples. In such events, high-energy particles or shocks from the flare site impart momentum to the plasma, launching waves that travel through the interior at sound speeds of 10–100 km/s. A significant example occurred during the X-class flare on December 14, 2006, in active region NOAA 10930, producing one of the strongest recorded helioseismic responses, with initial surface velocities reaching about 1 km/s and ripples expanding at up to 100 km/s. Ongoing convective activity also sustains background oscillations, but flares amplify specific high-amplitude modes. These helioseismic events enable detailed inference of the solar interior's and dynamics. By analyzing p-mode travel times and frequencies, researchers map variations in rotation rates—faster at the equator than poles—and density profiles, revealing in the . Wave speeds provide constraints on temperature and composition gradients. For waves (f-modes), a simplified asymptotic relation for the mode is given by νn,l≈l(l+1)2πcR,\nu_{n,l} \approx \frac{\sqrt{l(l+1)}}{2\pi} \frac{c}{R},
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