Articles in 2017

Ancient lavas reveal the presence of deep mantle reservoirs with anomalously light oxygen signatures. These lavas fingerprint heterogeneous mantle domains in early Earth that may have since been mixed away.

Lavas sourced from Archaean mantle plumes have anomalously light oxygen isotope signatures, according to geochemical analyses of lava samples from southern Africa. The results imply that Earth’s early mantle was heterogeneous.

Interactions between narrow frontal currents and topography in the Drake Passage enhance bottom mixing, according to ocean glider observations. Such interactions between frontal currents and topography could help close Southern Ocean overturning.

The Juan de Fuca plate, which subducts below the Cascades, is remarkably dry, according to reconstructions of water content based on seismic data. Decompression rather than hydrous melting must therefore be responsible for Cascades volcanism.

Niobium may be sequestered into the cores of some asteroids rather than remaining in their mantles according to measurements of meteorites and partitioning experiments. Accretion of such asteroids may explain why Earth’s mantle is depleted in niobium.

Many of the world's saline lakes have been shrinking due to consumptive water use. The Great Salt Lake, USA, provides an example for how the health of and ecosystem services provided by saline lakes can be sustained.

Satellite measurements indicate that Greenland's meltwater rivers are exporting one billion tons of sediment annually, a process that is controlled by the sliding rate of glaciers. This rate is nearly 10% of the fluvial sediment discharge to the ocean.

The production and consumption of organic carbon in inland waters varies with water residence time and biotic processes, suggest analyses of dissolved organic carbon from Northern Hemisphere water bodies. Inland waters mediate carbon transport between land and ocean.

Approximately 8% of the fluvial suspended sediment exported to the world’s oceans comes from rivers draining the Greenland ice sheet, according to an analysis of satellite imagery. Furthermore, the export is dominated by areas where subglacial erosion is high.

Quality requirements for water differ by intended use. Sustainable management of water resources for different uses will not only need to account for demand in water quantity, but also for water temperature and salinity, nutrient levels and other pollutants.

Extreme methane rainstorms on Titan occur in mid-latitudes, where alluvial fans are most common, according to a general circulation model. Average precipitation rates are insufficient to actively shape Titan’s surface.

Substantial amounts of organic carbon have been buried in the Wax Lake delta, USA, over the past 20 years, according to sediment analyses. This suggests that river diversions can lead to both coastal accretion and carbon sequestration.

Vertical migration of organisms and deep currents control the transport and characteristics of particles at the equator, according to an analysis of current and particle measurements. Particles fluxes are an important part of the ocean carbon cycle.

Over the past decade or so, China has turned into a land of opportunity for science. We are keen to witness first hand how the geoscience landscape continues to unfold.

The release of methane trapped in Martian subsurface reservoirs following planetary obliquity shifts may have contributed to episodic climate warming between 3.6 and 3 billion years ago, explaining evidence for ancient ice-covered lakes.

Debate rages over which water bodies in the US are protected under federal law by the Clean Water Act. Science shows that isolated wetlands and headwater systems provide essential downstream services, but convincing politicians is another matter.

Transient winter restratification events can promote phytoplankton blooms in the North Atlantic subpolar gyre, according to float data. Typical winter conditions feature a deep mixed layer that limits phytoplankton activity.

Bursts of methane stored in the Martian subsurface may explain intermittent warm climates on ancient Mars, according to numerical simulations. Sedimentary evidence for palaeolakes requires infrequent, yet sustained, lake-forming climates.

Enhanced protection is needed for freshwater bodies in the United States — in particular impermanent streams and wetlands outside floodplains — according to an assessment of their value and vulnerability.