Tuff Schist

The adventures of an unstable geologist

17 notes

caffeinateddiscoverer:

"For decades, geologists have debated the origins of an unmistakable curve in the Appalachian Mountains. Known to experts as the “Pennsylvania salient,” the bend begins in southern New York and northeastern Pennsylvania and extends across Pennsylvania to the border of Maryland. In this area, the ridges of the Appalachians turn from a roughly north-south orientation to an east-west orientation and then north-south again."

caffeinateddiscoverer:

"For decades, geologists have debated the origins of an unmistakable curve in the Appalachian Mountains. Known to experts as the “Pennsylvania salient,” the bend begins in southern New York and northeastern Pennsylvania and extends across Pennsylvania to the border of Maryland. In this area, the ridges of the Appalachians turn from a roughly north-south orientation to an east-west orientation and then north-south again."

(Source: earthobservatory.nasa.gov)

132 notes

Polonium’s most stable isotope gets revised half-life measurement

randdmag:

image

Scientists at NIST have determined that polonium-209, the longest-lived
isotope of this radioactive heavy element, has a half-life about 25%
longer than the previously determined value, which had been in use for
decades. The new NIST measurements could affect geophysical studies such
as the dating of sediment samples from ocean and lake floors.

Read More - http://www.rdmag.com/news/2014/09/polonium%E2%80%99s-most-stable-isotope-gets-revised-half-life-measurement

(via circuitdesign)

14 notes

tangledwing:

Nature’s coast guards

Barrier islands aren’t just for beach vacations — they protect coasts from storms and flooding.The United States has more than 400 barrier islands. That’s the most of any country. More than 1.4 million Americans live on barrier islands. Millions more visit them, especially in summer. Some barrier islands are famous for their vacation resorts, such as Fire Island in New York; Long Beach Island in New Jersey; North Carolina’s Outer Banks; Sanibel and Captiva islands in Florida; and South Padre Island in Texas. Other barrier islands have gained renown as parks and nature reserves that protect wildlife.But the biggest value that barrier islands offer is their ability to shield coastlines from the punishing force of ocean storms.Wind, waves and currents form and erode barrier islands. Although these islands can last for thousands of years, many today face serious threats. Key to their survival is the ability of these islands to shift and move in response to wind and waves. But when people cover barrier islands with roads, parking lots and buildings, they block the natural flow of sand. And that makes these islands erode more easily.Meanwhile, changes to the flow of onshore rivers have cut off the supply of sediments that replenish barrier islands. With global warming, sea levels have been rising. This means that with every wave, more water washes onto barrier islands. Scientists have also linked rising global temperatures to more and stronger ocean storms. So winds and waves strike the islands with more force, causing more damage.

tangledwing:

Nature’s coast guards

Barrier islands aren’t just for beach vacations — they protect coasts from storms and flooding.

The United States has more than 400 barrier islands. That’s the most of any country. More than 1.4 million Americans live on barrier islands. Millions more visit them, especially in summer. Some barrier islands are famous for their vacation resorts, such as Fire Island in New York; Long Beach Island in New Jersey; North Carolina’s Outer Banks; Sanibel and Captiva islands in Florida; and South Padre Island in Texas. Other barrier islands have gained renown as parks and nature reserves that protect wildlife.

But the biggest value that barrier islands offer is their ability to shield coastlines from the punishing force of ocean storms.

Wind, waves and currents form and erode barrier islands. Although these islands can last for thousands of years, many today face serious threats. Key to their survival is the ability of these islands to shift and move in response to wind and waves. But when people cover barrier islands with roads, parking lots and buildings, they block the natural flow of sand. And that makes these islands erode more easily.

Meanwhile, changes to the flow of onshore rivers have cut off the supply of sediments that replenish barrier islands. With global warming, sea levels have been rising. This means that with every wave, more water washes onto barrier islands. Scientists have also linked rising global temperatures to more and stronger ocean storms. So winds and waves strike the islands with more force, causing more damage.