Taxonomy term

Paleoclimate studies often depend on mineral or sediment layers deposited seasonally or annually in caves, lakes and ice, but such records leave gaps where caves, lakes or ice sheets aren’t found. Now, scientists using a new technique that analyzes calcite layers ringing pebbles and rocks in arid landscapes are opening a new window onto the climate history of western North America. And because such deposits are found all over the world, the technique might prove to be a useful new tool for studying paleoclimate globally.

In the 1980s, a collection of bones from very small hominids was excavated from a cave in southwestern China, alongside a number of bones from a species of large red deer. Nicknamed the “Red Deer Cave people,” but not yet declared a distinct species, researchers previously dated radiocarbon in the sediments where the bones were found to about 14,000 years ago. In a new comparative study, the same team has now found that the hominids from which the bones came appear to have been similar to — although far smaller than — Homo habilis and Homo erectus, suggesting it could indeed be a new species.

In late March 2005, a magnitude-8.7 earthquake struck off the northwest coast of Sumatra, Indonesia, rupturing a portion of the Sunda Megathrust Fault and further terrorizing a region still reeling from the devastating 2004 Boxing Day earthquake and tsunami just three months prior. The March quake, however, could have been far larger than it was, according to new research. Scientists have identified a topographic barrier on the oceanic Indo-Australian Plate — which descends under the Sunda Plate in the Sumatra Subduction Zone — that may have stopped the 2005 rupture from propagating farther.

The U.S. Geological Survey (USGS) regularly releases National Seismic Hazard Maps that summarize hazards from potential ground shaking produced by faults around the country. This year, for the first time, those maps include not only natural earthquakes, but also earthquakes induced by human activities — particularly injection of wastewater produced during oil and gas extraction practices. The new maps were released Monday on the USGS website.