Salmon are beginning to swim up the Elwha River for the first time in more than a century. But University of Washington marine geologists are watching what’s beginning to flow downstream — sediments from the largest dam-removal project ever undertaken.
The 108-foot Elwha Dam was built in 1910, and after decades of debate it was finally dismantled last year. Roughly a third of the 210-foot Glines Canyon Dam still stands, holding back a mountain of silt, sand and gravel. (more…)
Antarctica’s topography began changing from flat to fjord-filled starting about 34 million years ago, according to a new report from a University of Arizona-led team of geoscientists.
Knowing when Antarctica’s topography started shifting from a flat landscape to one with glaciers, fjords and mountains is important for modeling how the Antarctic ice sheet affects global climate and sea-level rise. (more…)
Discovery resulted from study of amphibians in ponds
The richer the assortment of amphibian species in a pond, the more protection that community of frogs, toads and salamanders has against a parasitic infection that can cause severe deformities, including the growth of extra legs.
The findings, published in a paper in this week’s issue of the journal Nature, support the idea that greater biodiversity in large-scale ecosystems, such as forests or grasslands, may also provide greater protection against diseases, including those that affect humans.
A larger number of mammal species in an area may curb cases of Lyme disease, while a larger number of bird species may slow the spread of West Nile virus. (more…)
Scientists build new ‘tree of life’ for placentals, visualize common ancestor
Scientists have reconstructed the common ancestor of placental mammals–an extremely diverse group including animals ranging from rodents to whales to humans–using the world’s largest dataset of both genetic and physical traits. (more…)
The International North Greenland Eemian Ice Drilling (NEEM) project results indicate that melting of Antarctic ice sheet may have contributed more to sea level rise than melting of the Greeland ice sheet some 100,000 years ago
A new study that provides surprising details on changes in Earth’s climate from more than 100,000 years ago indicates that the last interglacial–the period between “ice ages”–was warmer than previously thought and may be a good analog for future climate, as greenhouse gases increase in the atmosphere and global temperatures rise.
The research findings also indicate that melting of the massive West Antarctic ice sheet may have contributed more to sea-level rise at that time than melting of the Greenland ice sheet. (more…)
Study simulating pressures in mantle beneath the ocean floor shows that rocks can melt at depths up to 250 kilometers
Magma forms far deeper than geologists previously thought, according to new research results.
A team led by geologist Rajdeep Dasgupta of Rice University put very small samples of peridotite, rock derived from Earth’s mantle, under high pressures in a laboratory.
The scientists found that the rock can and does liquify, at least in small amounts, at pressures equivalent to those found as deep as 250 kilometers down in the mantle beneath the ocean floor. (more…)
A multimedia feature published this week in the New York Times, “Pushing Science’s Limits in Sign Language Lexicon,” outlines efforts in the United States and Europe to develop sign language versions of specialized terms used in science, technology, engineering and mathematics.
The article shares newly defined signs for terms like “light-year,” “organism” and “photosynthesis.” It also describes a successful crowdsourcing effort started at the University of Washington in 2008 that lets members of the deaf and hard-of-hearing community build their own guide to the evolving lexicon of science.
“It’s not a dictionary,” explained Richard Ladner, a UW professor of computer science and engineering. “The goal of the forum is to be constantly changing, a reflection of the current use.” (more…)
