Ice shelves modulate Antarctica's contributions to sea-level rise. Regional-climate-model simulations and observations suggest historical ice melt intensification before collapse of Antarctic peninsula shelves, and project future melt evolution. The image shows the ice shelf edge off Antarctica.

Letter p927

IMAGE: © BLICKWINKEL / ALAMY STOCK PHOTO

COVER DESIGN: DAVID SHAND

The fate of old, recalcitrant dissolved organic carbon in oceans is unclear. Field samples show that loss during circulation in hydrothermal vents can account for the 40-million-year lifetime of recalcitrant dissolved organic carbon in oceans. The image shows hydrothermal fluids gushing from the crust into the deep North Atlantic Ocean at the Logatchev vent field.

Letter p856; News & Views p820

IMAGE: © MARUM — CENTER FOR MARINE ENVIRONMENTAL SCIENCES, UNIV. BREMEN

COVER DESIGN: DAVID SHAND

The dynamic components of coastal water level can add metres to water levels during extreme events. A data synthesis reveals that Pacific regional wave and water level fluctuations are closely related to the El Niño/Southern Oscillation. The image shows the wave run-up that was caused by an extraordinary storm on the Hasaki coast in Japan on 25 October 2006.

Article p801

IMAGE: PORT AND AIRPORT RESEARCH INSTITUTE, JAPAN

COVER DESIGN: DAVID SHAND

Faults are unlocked by earthquakes. Analysis of seismic data from the 2015 Nepal earthquake shows that only part of the Main Himalayan Thrust fault was unzipped by the quake, leaving much of the fault locked and ready to slip in a future event. The image shows the Swayambhunath temple in Kathmandu basin eight days after the M w 7.8, Gorkha earthquake of April 2015.

Letter p708

IMAGE: CLAUDETTE RIBARDIÈRE

COVER DESIGN: DAVID SHAND

The role of static versus dynamic stresses in earthquake clusters is unclear. Analysis of earthquakes triggered by a dyke intrusion at an Icelandic volcano unambiguously demonstrates that static stresses are important for earthquake clustering. The image shows the Holuhraun fissure eruption in Iceland on 2 September 2014.

Letter p629

IMAGE: BOB WHITE

COVER DESIGN: DAVID SHAND

Strong vortices have been observed at Saturn's poles. Simulations suggest that tropospheric polar flows on giant planets are driven by moist convection, and that although vortices can develop on Saturn, similar cyclones are not expected on Jupiter. The image shows the spinning vortex of Saturn's north polar storm in a false-colour image from NASA's Cassini spacecraft, taken on 27 November, 2012.

Letter p523; News & Views p503

IMAGE: NASA/JPL-CALTECH/SSI

COVER DESIGN: DAVID SHAND

Fjords have been hypothesized to be hotspots of organic carbon burial. New data from New Zealand and a global compilation of organic carbon data and sedimentation rates shows that fjords sequester carbon at a rate five times higher than other ocean regions. The image shows the view of Doubtful Sound, Fiordland, New Zealand, from the RV Pelican.

Letter p450; News & Views p426

IMAGE: CANDIDA SAVAGE

COVER DESIGN: DAVID SHAND

Liquid water on equatorial Mars is inconsistent with large-scale climatic conditions. Humidity and temperature measurements by the Curiosity rover support the formation of subsurface liquid brines by hydration of perchlorates during the night. The image is a colour view of a Martian dune, taken by the Curiosity rover after crossing it during the 538th Martian day, or sol, of Curiosity's mission on Mars (Feb 9, 2014).

Letter p357

IMAGE: NASA/JPL-CALTECH/MSSS

COVER DESIGN: DAVID SHAND

Our understanding of the interactions between clouds, circulation and climate is limited. Four central research questions — now tractable through advances in models, concepts and observations — are proposed to accelerate future progress. The image shows clouds over the tropical North Atlantic, photographed during the NARVAL (Next-generation Aircraft Remote-sensing for Validation Studies) campaign.

Perspective p261

IMAGE: BJORN STEVENS

COVER DESIGN: DAVID SHAND

The processes that create economic-grade accumulations of metals above magma chambers are unclear. High-temperature laboratory experiments show that rapid reactions between magmatic gases and Earth's crust can trigger efficient metal deposition. The image shows the Grasberg Copper-Gold-Silver porphyry deposit in Papua, Indonesia, which contains reserves of well over 24 Mt of copper and 2,000 t of gold.

Letter p210; News & Views p168

IMAGE: KURT FRIEHAUF

COVER DESIGN: DAVID SHAND

Holocene temperature trends in the Arctic are unclear. An isotope record from ice wedges in Siberia suggests that winters have warmed since the mid-Holocene, whereas summer temperatures have cooled. The image shows a Pleistocene ice wedge on Muostakh Island, North Siberia, in August 2012.

Letter p122

IMAGE: THOMAS OPEL

COVER DESIGN: DAVID SHAND

Increasing CO2 concentrations are expected to increase plant growth and water efficiency. Tree-ring data covering 150 years from tropical forests show that water-use efficiency has increased with CO2 concentrations but tree growth has not. The image shows the sunset over a rain forest in the Amazon.

Letter p24; News & Views p4

IMAGE: PETER VAN DER SLEEN

COVER DESIGN: DAVID SHAND