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Patrick Lajeunesse and colleagues enjoyed the picturesque environment of Hudson Bay while mapping its floor in order to understand the nature of the catastrophic outburst flood of Lake Agassiz-Ojibway.
International Polar Year is drawing attention to the poles. But if more people are entering this pristine environment as a result, any negative impacts must be justified with commensurate benefits.
Whether convection in the Earth's mantle extends through its entire depth or if the mantle is layered has long been debated. Recent research suggests that spatially and temporally intermittent or partial layering is the most likely solution.
Earthquake data seem to reveal a huge sausage-shaped slab of material detaching itself from the material subducting as two plates meet beneath the Hindu Kush. This largest-ever 'boudin' could tell us more about what happens when continents collide.
Numerous long, wall-like ridges can be observed in the Valles Marineris region of Mars. They probably represent fault zones cemented by water-deposited minerals and are indicative of ancient groundwater flow.
Deltas are among the most valuable coastal ecosystems, but they are very dynamic and the factors that influence their health are complex. The rate of compaction of underlying sediments might be a more significant factor than was thought.
Lakes dammed by ice will commonly spill in catastrophic outbursts. Lake Agassiz-Ojibway, at the margin of the Laurentide ice sheet, burst 8,470 years ago in a subglacial flood whose marks have been scratched into the seafloor of Hudson Bay.
International Polar Year 2007–2009 had three predecessors 125, 75 and 50 years ago. These international research efforts were not free from geopolitical interests.
Arc-shaped scours, sandwaves and channels on the Hudson Bay seafloor suggest that the catastrophic drainage of lake Agassiz–Ojibway occurred as a subglacial flood beneath the Laurentide Ice Sheet, which covered northern North America.
A large lens-shaped feature bounded by shear zones characterizes the remnant slab beneath the Hindu Kush region. Rather than dripping by viscous flow, the slab is actively stretching and might eventually break off before descending further into the underlying mantle.
Long linear ridges in the Valles Marineris region of Mars most likely represent fault zones that have been cemented by water-deposited minerals. This implies that water in the Martian crust could have traversed long distances via faults and fractures.
Dust input to alpine lakes in the western United States has risen dramatically following westward expansion of human settlements and increased livestock grazing over the past two centuries. The increased dust flux deposits additional nutrients and minerals to the lakes, with important implications for water chemistry, productivity and nutrient cycling.
Despite Titan's cold temperatures (about 93.7 K at the equator), fluvial and atmospheric processes are active on this moon of Saturn, with methane playing a similar role to water on Earth. However, Titan lacks a global methane ocean, and rainfall appears to be episodic.
Over the last twenty years, changes in the shoreline between the Amazon and Orinoco rivers have largely been controlled by the 18.6 year tidal cycle. By 2015 AD, the tidal cycle will account for 90 metres of shoreline retreat in French Guiana and 6 centimetres of sea level rise.
