Volume 4 Issue 3, March 2011

As the science of attributing climatic extremes to human actions matures, lawyers are working through the implications for their trade.

Children everywhere are fascinated by the sky, stars and Sun. Emerging evidence from cultures throughout the world suggests that even young children can acquire knowledge of the Earth and its place in the Universe.

The contribution of the East Antarctic ice sheet to the 120 m of sea-level rise since the Last Glacial Maximum is unclear. New terrestrial and marine data suggest the thinning of East Antarctic ice was responsible for only a metre of this rise.

Continental crust is less dense than that of the oceans, and less likely to sink into the mantle. Nevertheless, an analysis of a high-pressure rock from the Swiss Alps suggests that more than one cycle of crustal sinking and return is possible.

The neurotoxin methylmercury accumulates in marine biota and their predators. An analysis of seabird egg shells suggests that sea-ice cover reduces the breakdown of this highly toxic compound in sea water.

Massive amounts of natural gas catastrophically released into the Gulf of Mexico last year are missing. Two investigations suggest that a bloom of tiny specialized bacteria is responsible for this heavy-duty scrubbing job.

Extreme climate events can cause widespread damage and have been projected to become more frequent as the world warms. Yet as discussed at an interdisciplinary workshop, it is often not clear which extremes matter the most, and how and why they are changing.

Hydrothermal vents in the sea floor release large volumes of hot, metal-rich fluids into the deep ocean. Mounting evidence suggests that organic compounds bind to and stabilize metals in hydrothermal fluids, thereby increasing metal flux to the open ocean.

The extent of snow cover and sea ice in the Northern Hemisphere has declined since 1979, suggesting a positive feedback of surface reflectivity on climate. A synthesis of a variety of remote sensing and field measurements suggests that this albedo feedback from the Northern Hemisphere cryosphere falls between 0.3 and 1.1 W m⁻² K⁻¹.

The present state and future evolution of Himalayan glaciers has been controversial. An analysis of remotely sensed frontal changes and surface velocities from glaciers in the greater Himalaya between 2000 and 2008 shows large regional variability in the responses of Himalayan glaciers to climate change.

The deep-sea oil spill in the Gulf of Mexico released large quantities of oil and gaseous hydrocarbons into the deep ocean. Calculations using published estimates of the volume of oil released suggest that up to 500,000 t of gases such as methane were released into the deep ocean.

The origins of the non-mass-dependent oxygen isotope anomaly in planetary materials remain controversial. An analysis of the carbon and oxygen isotopes of organic matter from a carbonaceous chondrite suggests that the signature was acquired in the envelope of the protosolar nebula, triggered by the photodissociation of carbon monoxide.

The Early Cretaceous greenhouse interval may have been punctuated by cooler periods. A reconstruction of sea-surface temperatures from low and middle latitudes shows no evidence of such cold events.

The M_w 8.8 Chile earthquake on 27 February 2010 occurred in a broad region where tectonic loading has been accumulating since the great 1835 earthquake. A joint inversion of tsunami and geodetic data suggests that the 2010 earthquake rupture only partly overlapped with the zone of preseismic locking.

The Adula nappe, Central Alps, was thought to be a mélange of rock fragments, some of which were subducted and then exhumed from the mantle. Lu–Hf dating of two populations of garnets in one rock sample instead indicates that the nappe twice experienced subduction and exhumation as one coherent unit.

During supercontinent cycles, deformation of continental lithosphere is observed to be concentrated near the plate boundaries. Global maps indicative of the strength of the lithosphere and its directional dependence show that strain is concentrated at pre-existing zones of weakness.

Atmospheric deposition of mercury to remote areas has increased threefold since pre-industrial times. Reductions in sea-ice cover accelerate the photodegradation of biologically accessible mercury in Arctic waters, according to an analysis of the isotopic composition of bird eggs in northern latitudes.

The East Antarctic ice sheet retreated at the end of the last glacial period. Terrestrial and marine data suggest that the retreat began 14,000 years ago, indicating that the East Antarctic ice sheet probably did not contribute to meltwater pulse 1a 14,700 years ago.

Continental lithosphere can undergo pervasive internal deformation, but patterns of flow within the lithosphere are difficult to observe. Determination of seismic Rayleigh-wave anisotropy in the crust and mantle of the Aegean region reveal matching orientations of regional-scale anisotropic fabric and the directions of extension during the last significant episodes of deformation.

Samantha Joye and her colleagues donned respirators and safety suits to survive the fumes when tracing an underwater gas plume following the Deepwater Horizon disaster.