Articles in 2016

Large earthquakes are often assumed to reset the seismic hazard of a region. Analysis of recent and historical seismicity in Ecuador suggests that this region may experience clusters of large earthquakes and extended periods of high seismic hazard.

Pressure during subduction is thought to reduce porosity and restrict water escape from the slab. Thermodynamic modelling shows that channel networks, which grow around local chemical heterogeneities, can help drain the subducting plate.

The dynamics of polar marine ecosystems are poorly understood. A laser-based space-borne sensor captures annual cycles of phytoplankton biomass in seasonally ice-free polar waters, and provides clues on how growth drives these cycles.

Phytoplankton productivity is high in the polar oceans. Lidar observations from 2006–2015 reveal that phytoplankton biomass was characterized by annual cycles influenced by sea-ice extent in the Antarctic and ecological processes in the Arctic.

The MESSENGER spacecraft has revealed geochemical diversity across Mercury’s surface. Magma crystallization experiments suggest a crustal mineralogy consistent with a transition towards shallower and cooler mantle melting conditions.

The controls on fast versus slow fault slip in subduction zones are unclear. Rock deformation experiments suggest that faults within the seismogenic region of a subduction zone may slip aseismically due to pressure solution creep.

Satellite observations have detected localized magnetic field changes at high latitudes. Simulations suggest these changes can be explained by a westward jet in the liquid core, which has been accelerating over the past 15 years.

Abrupt climate changes in the glacial North Atlantic altered the position of wind systems in the Northern Hemisphere and tropics. Ice-core data show that this disruption also reached the southern westerlies.

180 million years ago Earth's continents were amalgamated into one supercontinent called Pangaea. Analysis of oceanic crust formed since that time suggests that the cooling rate of Earth was enhanced in the wake of Pangaea's dispersal.

Ocean acidification can affect growth and calcification rates of calcifying phytoplankton. Mesocosm experiments reveal that acidification can also cause declines in population size and inhibit bloom formation.

Thicker oceanic crust forms from a hot mantle. Observations of unusually thick oceanic crust that formed 170 million years ago in the Atlantic and Indian oceans suggest that the ancient supercontinent Pangaea helped insulate and warm the mantle.

Abrupt glacial climate changes were slowly communicated between hemispheres by oceanic heat transport. Ice core data point to more rapid atmospheric teleconnections linking the North Atlantic, tropics, and southern storm track.

Glaciers have been retreating almost globally over the past century. An analysis using signal-to-noise ratio as a metric of individual glacier change reveals that glacier retreat constitutes categorical evidence for regional climate change.

Rocks are altered by high pressure during subduction. Analysis of exhumed metamorphic rocks suggests that the peak pressures recorded within minerals mark a change in tectonic regime within a subduction zone, rather than burial depth.

Nitrogen losses have not been observed in the Bay of Bengal, unlike in other ocean oxygen minimum zones. Chemical and molecular analyses reveal that trace levels of oxygen inhibit nitrate formation, largely preventing microbial N₂ production.

The clock is ticking for climate change mitigation. Geoengineering is gaining ground as an option, but it needs to be examined at a large scale to determine its effectiveness and associated risks.

Organic carbon decomposition in anoxic marine sediments was thought to be dominated by bacteria, but experimental data and microbial culture studies now show that microalgae buried in coastal sands may also play an important role in carbon turnover.

The Moon is thought to have initially had a magma ocean that gradually solidified. Crystallization experiments find that the resulting crustal thickness depends on water content and is consistent with significant water in the early Moon.