Articles in 2012

Freshwater availability is likely to change in many regions. Humans must adapt — or move.

Not enough young people enter the geosciences. A passion for the subject should be sparked early on.

Multiple factors determine how much water is and will be available in the river basins of Asia. To expose hotspots and help adaptation, these factors must be assessed together at the basin level.

The catastrophic drainage of glacial Lake Agassiz about 8,500 years ago is linked to abrupt climate change. A layer of sediments deposited during the previous interglacial period suggests that such outburst flooding is not unique to the Holocene epoch.

Ocean acidification is predicted to harm the ocean's shell-building organisms over the coming centuries. Sea butterflies, an ecologically important group of molluscs in the Arctic and Southern oceans, are already suffering the effects.

As a result of ocean acidification, aragonite may become undersaturated by 2050 in the upper layers of the Southern Ocean. Analyses of sea snail specimens, extracted live from the Southern Ocean in January and February 2008, show that the shells of these organisms are already dissolving.

The current mountain pine beetle infestation in forests in British Columbia ranks among the largest ecological disturbances recorded to date. An analysis of remote sensing data suggests that the resultant forest loss has led to a 1 °C rise in summertime surface temperatures.

The West Antarctic Ice Sheet is sensitive to ocean warming and contains enough ice to significantly raise sea level. Direct oceanographic measurements in the Amundsen Sea during 2010 show continuous inflow of warm water towards the thinning ice shelves in West Antarctica.

The mantle plume beneath Hawai’i shifted southwards by about 15° between 80 and 50 million years ago. Palaeomagnetic inclination data from four South Pacific seamounts along with Ar/Ar dating reveal that by contrast the Louisville hotspot—Hawai’i’s southern hemisphere counterpart—remained within 3° of its present latitude between 70 and 50 million years ago.

Diatoms—unicellular algae that form substantial blooms in cold, nutrient-rich waters—are thought to be responsible for the export of marine silica to depth. An analysis of the elemental composition of marine cyanobacteria suggests that picocyanobacteria also accumulate significant quantities of silicon.