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Counter-rotating gases demonstrate external gas acquisition in galaxies, but their presence in blue, star-forming galaxies has not been studied systematically. Here, the authors analyse the MaNGA survey data to find a fraction of counter-rotators among blue galaxies whose central regions show ongoing growth.

Information on stellar populations of the grand-design spiral galaxy UGC 3825 is exploited to measure the offset between young stars of a known age and the spiral arm in which they formed. The measured offset is consistent with a quasi-stationary density wave.

Following the Mw6 South Napa earthquake in California, previously dry streams and springs began to flow. Here, the authors present data from repeated stream surveys and laboratory measurements and suggest that the new flows originated from groundwater in the mountains and were released by the earthquake.

Evidence for a past large explosive eruption within the Santorini caldera suggests that early stages of silicic caldera cycles can be more hazardous than previously assumed, according to analyses of intra-caldera deposits from the Kameni Volcano.

Several moons in the outer Solar System have oceans encased beneath an ice shell. If the ice shell thins, ocean pressure decreases. Modelling shows that on Mimas, Enceladus, and Miranda, the ocean can boil. On larger bodies, instead, compressional forces form tectonic features.

Oxide nanolites crystallisation in natural magma increases melt, and hence bulk magma viscosity mainly due to iron extraction. This increase can be sufficient to drive magma fragmentation depending on magma degassing and ascent dynamics.

Enceladus’s tiger stripes at the south pole formed in cascade and spaced equally after the first fracture—probably Baghdad Sulcus—was created by the release of accumulated tensile stress, caused in turn by secular cooling.

Ancient shorelines on Mars must have formed before and during the emplacement of the Tharsis volcanic province, instead of afterwards as previously assumed, suggesting that oceans on Mars formed early.

Creep and earthquakes produce distinct microstructural fabrics, representing a form of material memory that can be created and erased through the seismic cycle, according to X-ray microtomography of sediments within the San Andreas fault zone.

Early 2018 saw unusually heavy rainfall in Hawaii. Modelling now suggests that groundwater pressure increased owing to rainfall: this might have triggered changes in the eruption of the island’s Kīlauea volcano.

The size of the caldera formed when the surface collapses after a large volcanic eruption is thought to reflect the size of the evacuated magma chamber. Numerical modelling shows that magma stored in different parts of the chamber can be mobile or locked, so caldera size may only correspond to the volume of evacuated mobile magma.

Volcanic eruptions can inject hazardous ash clouds into the atmosphere. Numerical simulations and experiments on volcanic rock samples show that clasts initially formed deep in the volcanic conduit break-up during collisions in the conduit, thus generating fine-grained clouds of ash.

The surface of Mars has a set of features that ring the plains for thousands of kilometres, which have been interpreted as a series of former shorelines. But topographic profiles along the putative shorelines contain long-wavelength trends in elevation that have been taken as an argument against the shoreline (and ocean) hypothesis. This paper demonstrates that true polar wander could bring the elevations of the proposed shorelines into line, reviving the ocean hypothesis.

Eruptive styles at a single volcano may transition from explosive to effusive behaviour (or vice versa) at any given time. This review examines the underlying controls on eruptive styles such as magma viscosity, degassing and conduit geometry at volcanoes with silicic compositions.

In a Hawaiian fountain eruption, rapid gas expansion cools the melt below the glass transition temperature and causes brittle magma fragmentation, producing small, vesicular pyroclasts, according to observations of the 2018 eruption of Kīlauea.

The 2014 South Napa earthquake in California caused increased streamflow and diurnal fluctuations in Sonoma Creek due to amplified interaction between rising water table and plant roots in the riparian zone, according to results from numerical simulations constrained by streamflow record and hydraulic properties of the riparian sediments.

The authors investigate the groundwater table changes in the Kumamoto region (Japan) following the 2016 M_w 7.0 Kumamoto earthquake. Through detailed isotope analysis the study shows how earthquakes can rupture the crust and generate new pathways for aquifers.

Α combined study of spatially resolved stellar kinematics and global stellar populations with the SAMI Galaxy Survey finds a strong correlation between the characteristic stellar population age of a galaxy and its intrinsic ellipticity.

Local microenvironmental cues modulate melanocyte stem cells, which control hair pigmentation, to enter different differentiation states, shifting between hair follicle stem cell and transit-amplifying compartments, a process that is different to other self-renewing systems.

It is difficult to obtain a dynamic picture of the Earth's mantle. A study involving geophysical observations with geochemical implications shows that compositionally distinct megablobs contribute to the ebb and flow.

The spatiotemporal evolution of fluid-induced microearthquakes can be accurately forecasted using a transformer-based deep learning approach trained on hydraulic stimulation and microseismic history from the EGS Collab field experiment.

A large shallow submarine explosive eruption of ancestral Santorini Volcano discharged pyroclastic gravity flows that laid down an extensive rhyolitic volcaniclastic deposit, identified in drill cores from the Southern Aegean seafloor