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september 2009

Redefining Quaternary

Blogging on EARTH

The Quaternary Period — the geologic time period that includes human evolution up to the present — is now a bit longer than it used to be.

04 Jun 2009

Geology 101: Reading the story in the rocks

David Harwood’s field geology course gives future teachers an introduction to several of geology’s most fundamental principles, including the stratigraphic basics described by Nicholas Steno in 1669. Go to the head of the class with this quick primer.

20 Oct 2009

Earthquake rocks Sumatra

Updated on Oct. 1:

A second, magnitude-6.6 earthquake struck southern Sumatra, Indonesia, today at about 8:52 a.m. local time; this time, the epicenter was 215 kilometers southeast of Padang, West Sumatra. The death toll from both events has risen to at least 531 people.

30 Sep 2009

Powerful earthquake strikes Samoa

Updated on Sept. 30:

A tsunami spawned by Tuesday's earthquake, which struck in the Pacific Ocean between American Samoa and Samoa, swept across the islands on Tuesday, local authorities reported Wednesday. Authorities in the region are reporting that the death toll from the earthquake and tsunami has risen to at least 111 people, including 22 people in American Samoa, 82 people in Samoa and seven in Tonga, according to a report by CNN.

29 Sep 2009

Moon much wetter than thought

The moon isn’t quite the bone-dry place scientists once thought; instead, its surface is covered in water, according to a landmark finding announced by scientists at NASA today.

24 Sep 2009

Getting a master's in social geology

At first glance, it seems like an obvious solution to a problem: Villagers need vegetables and an aid organization has money to buy tools and seeds. Striving to create a sustainable program, the aid organization develops a training plan to teach the villagers how to garden, invests in local workshops, and purchases tools to distribute to the participants. All plans seem in order and the project is poised for success. However, the project’s managers encounter the first of potentially many obstacles when they realize that shovels are impossible to use if you don’t have shoes.

24 Sep 2009

Musical magnetic reversals

Although Earth’s magnetic field currently points toward the North Pole, the planet’s magnetic dipole flips direction every few hundred thousand years or so. Engebretson tracked the last 85 million years of these magnetic reversals, with higher pitches representing shorter polarities (a period of time when the direction of the magnetic field stays the same), and lower pitches longer ones.

22 Sep 2009

Earth tides in A major

Earth experiences small, millimeter-sized tides, called Earth tides. Using a dataset from NASA’s Jet Propulsion Laboratory in California from A.D. 1600 to A.D. 2200, Engebretson calculated the net gravitational force of the sun and the moon at particular intervals and then mapped them onto the A major scale.

22 Sep 2009

The cosmos on key

Engebretson’s latest project involves taking the orbital periods of all eight planets in the solar system and turning them into corresponding frequencies: Planets that have short orbits like Mercury have higher frequencies, whereas more distant planets with longer orbits like Neptune have lower frequencies.

22 Sep 2009

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