Research articles

Nanoscale evidence suggests that the Tumbiana Formation stromatolites in Australia were influenced by microbial activity. In the stromatolites, clusters of organic globules are closely associated with 2,724-million-year-old aragonite crystals.

The occurrence of lower-hybrid solitary structures in the ionoshere are triggered by lightning-induced whistlers, revealing a new coupling process between the troposphere and the ionosphere.

It may be possible to predict eruptions of the Piton de la Fournaise volcano by continuously monitoring changes at depth using very small fluctuations in the ambient seismic noise. The changes are probably related to inflation caused by movement of magma at depth.

A strong radar reflection in the West Antarctic ice sheet is related to the eruption of the newly identified Hudson Mountains Subglacial Volcano dated to 207 BC. This eruption probably caused short term changes in regional glacial and meltwater flow.

A significant fraction of the anthropogenic nitrogen input into the coastal oceans from fertilizers is transferred back to land by commercial fisheries.

The final geometry of an impact crater can be significantly influenced by the geological and geomorphological structure of the impact site; therefore, it may not on its own provide accurate information regarding the direction and angle of impact.

Observed estimates of ice losses in Antarctica combined with regional modelling of ice accumulation in the interior suggest that East Antarctica is close to a balanced mass budget, but large losses of ice occur in the narrow outlet channels of West Antarctic glaciers and at the northern tip of the Antarctic peninsula.

Increasing levels of atmospheric carbon dioxide leads to ocean acidification, causing significant reductions in the growth of crustose coralline algae.

The speed of a glacier is affected most by sudden jumps in the water supply to the glacier, but it goes back to previous levels if high water inputs are sustained because the glacier's plumbing system adjusts.

The isotopic composition of oceanic basalts suggests that they are composed of true recycled oceanic crust and sediments, which are mixed with the depleted mantle.

The Great Ordovician Biodiversification Event coincides ~470 million years ago with the break-up of a large asteroid and the resultant frequent bombardment of Earth with asteroid fragments.

Sea level during the last interglacial stood at least 4 m higher than at present, with evidence of short-term fluctuations of up to 10 m. A new continuous sea level record from the Red Sea and coral ages suggest that during these fluctuations, sea level changes were on the order of 1.6 m per century.

Clustering of earthquakes at various spatial scales is the result of a heterogeneous distribution of stresses, and – at least for intermediate-magnitude earthquakes – areas that are quiet at present are likely to remain so in the future.

Carbon isotopes of fossil plants and model simulations suggest that atmospheric carbon dioxide levels were variable during the period 200 to 60 million years ago. The large decreases in the partial pressure of CO₂ coincide with glaciations, providing evidence against climate–CO₂ decoupling during the Mesozoic.

Over the past 15 million years, Arctic Ocean circulation has exhibited two distinct modes: during the interglacial periods of the past two million years, including the present, Arctic intermediate water was mainly derived from North Atlantic inflow. By contrast, between 15 and 2 million years ago, and during glacial periods thereafter, brine formation on the Eurasian shelves contributed substantially to Arctic intermediate water.

Multibeam mapping of the northwestern Indian Ocean seafloor provides clear evidence of dextral strike-slip motion along the Owen fracture zone and helps constrain the nature of deformation as well as the rate of slip along this little-studied plate boundary.