Nicaragua volcano spews tons of ash

Nicaragua's San Cristobal volcano shot tons of ash into the sky after forcing evacuations of nearby towns, officials said.

Sunset Crater, San Francisco Volcanic Field

The San Francisco Volcanic Field is a 4,700 square kilometers (1,800 square miles) area in the southern boundary of the Colorado Plateau. The field contains more than 600 scoria cones active in the past six million years. ...

Popcorn-rocks solve the mystery of the magma chambers

Since the 18th century, geologists have struggled to explain how big magma chambers form in the Earth's crust. In particular, it has been difficult to explain where the surrounding rock goes when the magma intrudes. Now a ...

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