Solid Earth sciences

Analysis of inherited zircons and sanidines from Miocene ignimbrites in the Central Andes shows that plutons were emplaced for up to 4 million years prior to onset of volcanism and that disruption of plutonic rock occurs a few decades or less just before or during super-eruptions.

An explanation of the Earth’s ‘missing Xe’ problem that involves multiple magma ocean stages combined with atmospheric loss is proposed.

Using the new Beaumont number presented, it is concluded that the topographic evolution of collisional mountain belts is determined by the combination of plate velocity, crustal rheology and surface process efficiency.

Lab experiments show that spontaneously propagating ruptures navigate fault regions through intermittent slip with dramatic friction evolution, providing support that weakening mechanisms may allow ruptures to break through stable faults.

Oceanic plate carbon reservoirs are reconstructed and the fate of subducted carbon is tracked using thermodynamic modelling, challenging previous views and providing boundary conditions for future carbon cycle models.

A deep learning model trained on prompt elastogravity signal (PEGS) recorded by seismometers in Japan predicts in real time the final magnitude of large earthquakes faster than methods based on elastic waves.

By combining experimental constraints on mantle melting with magnetotelluric data, volatile-rich melts emplaced by a mantle plume were shown to be present in the asthenosphere beneath the Cocos Plate.

Reconstruction of one billion years of mantle flow shows that mobile basal mantle structures are just as consistent with the Earth’s volcanic history as are fixed mantle structures.

High-resolution images derived from airborne geophysical data reveal critical aspects of the Yellowstone hydrothermal system, which can be used to assess geochemical models of the evolution of thermal fluids worldwide.

At temperatures and pressures typical of the Earth’s lower mantle, cubic CaSiO₃ perovskite is found to have lower strength and viscosity compared to bridgmanite and ferropericlase, providing clues to its role in subduction regions.

Molecular dynamics simulations show that the light elements hydrogen, oxygen and carbon become highly diffusive like liquid in solid iron under the inner-core conditions, leading to a reduction in the seismic velocities.

Geochemical analyses correlating the stratum that overlies the sediments containing the Omo fossils with material from a volcanic eruption suggest that these fossils (the oldest known modern human fossils in eastern Africa) are over 200,000 years old.

X-ray diffraction experiments indicate that the depression of the Earth’s 660-kilometre seismic discontinuity beneath cold subduction zones is caused by a phase transition from akimotoite to bridgmanite, leading to slab stagnation.

Variations in Miocene sea level can be explained by a large marine-based West Antarctic Ice Sheet.

The krypton isotopic pattern of Earth’s deep mantle indicates that volatile-rich material from the outer Solar System was delivered early in Earth’s accretion history.

Numerical subduction models used to determine the consequences of bending-induced plate damage show that slab weakening and segmentation can occur at the outer-rise region of the subducting plate.

Lake breach flooding rapidly eroded almost a quarter of the volume of incised valleys on early Mars, influencing the topography of the wider Martian landscape.

A record of Earth’s magnetic field constructed from near-bottom magnetization observations and oriented samples provides three-dimensional imaging of magnetic stripes in fast-spread crust, and suggests slow cooling off-axis, as opposed to deep hydrothermal cooling close to the spreading ridge.

Cratons are the oldest parts of the Earth’s continents; this Review concludes that the production of widespread, thick and strong lithosphere via the process of orogenic thickening was fundamental to the eventual emergence of extensive continental landmasses.

A multidisciplinary method for managing triggered seismicity is developed using detailed subsurface information to calibrate geomechanical and earthquake source physics models, and is applied to the Val d’Agri oil field in seismically active southern Italy.

Electromagnetic data collected at the northern Hikurangi Margin, New Zealand show that a seamount on the incoming plate allows more water to subduct, compared with normal, unfaulted oceanic lithosphere.

Thirty years of geothermal heat production at Coso in California depleted shear stresses within the geothermal reservoir, which changed its faulting style and inhibited aftershocks from the 2019 Ridgecrest earthquake.

Analysis of recurved cupules from a newly discovered Early Cretaceous silicified peat in Inner Mongolia, China and comparison with other potentially related Mesozoic plant fossils provides insight into the origins of angiosperms.

Upwelling of mantle plumes is proposed as a mechanism for craton healing after substantial disruption of their roots, enabling them to return to their original lithospheric thickness.

A model for eruptions resulting in caldera collapse reconciles observations of quasi-periodic stick–slip events along annular faults and the large erupted volumes characteristic of such events, highlighting the role of topography-generated pressures.

Rotated fault-plane solutions in earthquake swarms at volcanoes could provide an early indication of relatively viscous magma, and hence of the style and hazard potential of an impending eruption.

Oxygen isotopes and whole-rock geochemistry show that the water required to make Earth’s first continental crust was primordial and derived from the mantle, not surface water introduced by subduction.

Oceanic transform faults are systemically deeper than their associated fracture zones, owing to the plate boundary experiencing increasingly oblique shear at increasing depths below the seafloor.

Numerical simulations indicate that seismological observations of large megathrust earthquakes are better matched by crack-like ruptures on persistently weak faults than by self-healing pulse-like ruptures on stronger faults.

Amorphization at grain boundaries in olivine-rich rocks under stress and consequent grain-boundary sliding could explain the decrease in viscosity between the lithosphere and the asthenosphere.

Data from ocean bottom seismometers show that the mantle transition zone beneath the equatorial Mid-Atlantic Ridge is thin and warm, which suggests more material transfer than previously thought.

Estimates of global total biomass (the mass of all living things) and anthopogenic mass (the mass embedded in inanimate objects made by humans) over time show that we are roughly at the timepoint when anthropogenic mass exceeds total biomass.

A model is proposed for the origin of cratonic lithospheric mantle in which rifting and melting in the hot, early Earth mantle leave behind large volumes of stiffer, depleted mantle.

Changes in Northern Hemisphere ice-sheet size during ice-age cycles enhance the advance and retreat of the grounding line of the Antarctic Ice Sheet, owing to interhemispheric sea-level forcing.

Analysis of global three-dimensional shear attenuation and velocity models implies that partial melting in the seismic low-velocity zone enables motion of oceanic plates by reducing the viscosity of the asthenosphere.

Modelling reveals how thick diamondiferous continental mantle ‘keels’ were formed only at increased mantle temperatures when the melt-depleted, hot, ductile mantle located under subducting oceanic plates flowed backwards, underplating the continents.

Oxygen isotope measurements of mineral inclusions in superdeep diamonds indicate that carbonated igneous oceanic crust is the primary carbon-bearing reservoir in slabs subducted to deep-lithospheric and transition-zone depths.

Observed global-mean sea-level rise since 1900 is reconciled with estimates based on the contributing processes, revealing budget closure within uncertainties and showing ice-mass loss from glaciers as a dominant contributor.

Uranium isotopes in subglacial precipitates from the Wilkes Basin of the East Antarctic Ice Sheet reveal ice retreat during a warm Pleistocene interglacial period about 400,000 years ago.

Serpentine subducted below the Lesser Antilles volcanic arc supplies water to the arc, controlling the location of seismicity, volcanic productivity and thickness of crust.

Simulations using a force balance model match mountain heights observed around the globe, suggesting that mountain elevation is almost completely controlled by tectonic forces rather than erosion.

Carbon dioxide and helium data support lateral advection of carbon-rich cratonic mantle below the East African Rift System, which concentrates deep carbon and causes active carbonatite magmatism near the craton edge.

Observed reversals in GNSS surface motions suggests greatly enhanced slab pull in the months preceding the great subduction earthquakes in Maule (Chile, 2010) and Tohoku-oki (Japan, 2011) of moment magnitudes 8.8 and 9.0.

Immediately before and during the eruption of Kīlauea Volcano in May 2018, anomalously high rainfall increased the pore pressure in the subsurface to its highest level in 50 years, causing weakening and mechanical failure of the edifice.

Ruthenium isotope compositions of the oldest preserved mantle rocks from Greenland imply that volatile-rich outer Solar System material was not delivered to Earth until very late in the planet’s formation.

The widespread intraplate volcanism in northeast China and the unusual ‘petit-spot’ volcanoes offshore Japan could have resulted from the interaction of the subducting Pacific slab with a hydrous mantle transition zone.