Earth | Page 1010 | Science Codex

What lies beneath? New survey technique offers detailed picture of our changing landscape

A new surveying technique developed at The University of Nottingham is giving geologists their first detailed picture of how ground movement associated with historical mining is changing the face of our landscape.

The new development by engineers at the University has revealed a more complete map of subsidence and uplift caused by the settlement of old mines in the East Midlands and other areas of the country and has shown that small movements in the landscape are bound by natural fault lines and mining blocks.

Preserving van Gogh's priceless masterpieces

The chrome yellow pigment that renowned post-Impressionist artist Vincent van Gogh favored in priceless masterpieces like Sunflowers, the Yellow House and Wheatfield with Crows is especially sensitive to certain types of light and should be protected to prevent darkening. That's the conclusion of a series of studies in ACS' journal Analytical Chemistry, which could help preserve masterpieces by van Gogh and contemporaries like Gauguin, Cézanne and others.

Boosting the sensitivity of airport security screening

Scientists are reporting a simple way to improve the sensitivity of the test often used to detect traces of explosives on the hands, carry-ons and other possessions of passengers at airport security screening stations. Their report appears in ACS' The Journal of Physical Chemistry C.

Accelerated subglacial erosion in response to stick-slip motion

The form of many of the world's mountain ranges has been brought about through the erosive capabilities of the glaciers that lay upon them.

Glacial erosion is generally depicted as a steady process, occurring over long periods coupled with steady motion of the glaciers. It is becoming increasingly evident that glaciers do not always behave in a steady manner and that at times they can undergo rapid advancements over their base similar to the way an earthquake slips. The sudden slip generates seismicity that can be observed remotely.

Golden plumes: Substantial gold enrichment of oceanic crust during ridge-plume interaction

This article shows that mantle plumes -- hot, upwelling portions of the Earth's mantle -- create large quantities of gold-rich crust when they are melted. These gold-rich rocks contain up to 13 times the amount of gold in normal crust.

This means that crust created from mantle plumes represent a rich source of gold and other metals which could be incorporated into mineral deposits. As such, mineral deposits created by sourcing metals from such rocks may be larger or occur more frequently than deposits formed from normal crust.

Melting glaciers raise sea level

Coral record of reduced El Niño activity in the early 15th to middle 17th centuries

The El Niño-Southern Oscillation (ENSO) drives many of the catastrophic climate events that occur from one year to the next: floods, droughts, wildfires, and hurricanes.

However, climate scientists do not yet know how ENSO will respond to climate change. A new multi-century reconstruction of ENSO variability, based on fossil corals from Papua New Guinea, reveals a century-long decline in the number of El Niño events starting in the mid-1500s.

Grounding-line retreat of the West Antarctic Ice Sheet from inner Pine Island Bay 'unprecedented'

Over the last few decades, melting of West Antarctic glaciers has contributed significantly to global sea-level rise. Since 1992, two major outlet glaciers have experienced up to 25 km of landward retreat of their "grounding line," the position at which the glacier margin starts to float.

Late Pleistocene tropical Pacific temperature sensitivity to radiative greenhouse gas forcing

Understanding how global temperature changes with increasing atmospheric greenhouse gas concentrations, or climate sensitivity, is of central importance to climate change research.

Climate models provide sensitivity estimates that may not fully incorporate slow, long-term feedbacks such as those involving ice sheets and vegetation. Geological studies, on the other hand, can provide estimates that integrate long- and short-term climate feedbacks to radiative forcing.

Parallel volcano trends and geochemical asymmetry of the Society Islands hotspot track

Plumes of hot, buoyant material are thought to rise from the deepest mantle, near the core-mantle boundary.

In the shallow mantle, the plumes partially melt, and the melt is erupted at the surface at hotspot volcanoes. Several hotspot volcanoes, including those in Hawaii, Samoa, and the Marquesas, exhibit two parallel volcanic lineaments that are geochemically distinct. This geochemical separation is thought to result from the plumes being sourced from the northern side of a large, enriched geochemical and seismological anomaly in the deepest mantle.

A reduced relevance of vegetation change for alluvial aggradation in arid zones

This study by Jose Luis Antinao and Eric McDonald assesses the hypothesis that a climatically induced decrease in vegetation density on arid region hillslopes is a major factor behind erosion, sediment transport, and aggradation (sedimentation) downstream.

This linkage is often used to explain sedimentation in alluvial fans during the Late Pleistocene Holocene period (8 to 14-thousand years ago) in the U.S. Southwest deserts. Antinao and McDonald compiled paleo-botanical and alluvial fan sedimentation histories during this period in the Mojave and northern Sonoran deserts.

Silver Creek caldera -- The tectonically dismembered source of the Peach Spring Tuff

Charles Ferguson and colleagues describe the discovery of a volcano in the Mojave Desert of the southwestern United States that has implications for understanding the mechanism for super-eruptions, a class of volcanic eruption that taps very large (greater than 100 cubic kilometers) amounts of magma in a very short period of time (hours to days).

Pacific fishing zones -- lifeline for overfished tuna?

Marine zoning in the Pacific Ocean, in combination with other measures, could significantly improve numbers of heavily overfished bigeye tuna and improve local economies, a fish modelling study has found.

Preserve the services of mangroves -- Earth's invaluable coastal forests, experts urge

Experts are urging policy makers to preserve mangroves and their essential services to nature and humanity alike, saying their replacement with shrimp farms and other forms of development is a bad economic tradeoff both short and long-term.

Climate change increases stress, need for restoration on grazed public lands

CORVALLIS, Ore. – Eight researchers in a new report have suggested that climate change is causing additional stress to many western rangelands, and as a result land managers should consider a significant reduction, or in some places elimination of livestock and other large animals from public lands.