Alaska’s Umnak Island in the Aleutians showing the huge, 10-km wide caldera (upper right) largely created by the 43 BCE Okmok II eruption at the dawn of the Roman Empire. Landsat-8 Operational Land Imager image from May 3, 2014

Eruption of Alaska’s Okmok volcano linked to period of extreme cold...

Scientists examined hundreds of samples taken along the global ridges that contain recycled ancient oceanic crust in variable amounts. "Depleted" segments of the ridge received lower than "normal" amounts of recycled crust, while "enriched" segments contain a larger proportion of recycled crust.

Geochemists solve mystery of Earth’s vanishing crust

Mud Volcanoes

The geological record of mud deposits

Life reconstruction of the giant wombat relative Mukupirna nambensis on the shores of Lake Pinpa 25 million years ago. Also shown are stiff-tailed ducks (foreground) and flamingos (background), the remains of which are known from the same fossil deposit. Credit: Painting by Peter Schouten.

Big-boned marsupial unearths evolution of wombat burrowing behavior

Purple Amethyst

Purple Amethyst : What causes the purple color of amethyst?

The Roebling Opal

Roebling Opal : Amazing Rare blue and green Opal Found in...

Seismic recordings with bell ringing signals in four European locations to mark the passage of time: Lunas (France), Riolos (Greece), Sta. Marيa de Montmagastrell (Spain) y Oriolo (Italy). Each plot corresponds to one day. Each trace represents the same minute at every hour on that day. Time scale is in seconds. (Image: Jordi Dيaz, ICTJA-CSIC)

How seismometers record church bells ringing

A lump of coal weathering out from Siberian flood basalts in a quarry near the town of Ust Ilimsk Credit: Scott Simper

Coal-burning in Siberia led to climate change 250 million years ago

Earthquakes send sound waves through the Earth. Seismograms record the echoes as those waves travel along the core-mantle boundary, diffracting and bending around dense rock structures. New research from University of Maryland provides the first broad view of these structures, revealing them to be much more widespread than previously known. Credit: Doyeon Kim/University of Maryland

Scientists detect unexpected widespread structures near Earth’s core

The Andes seen from space. The height of the Andes, like the height of other mountain ranges on Earth, is determined by tectonic forces (Credit: NASA; Astronaut photograph ISS059-E-517).

Which factors control the height of mountains?

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