Taxonomy term

rift

Why tectonic plates lurch forward when they break

When continents rift, they often do so slowly at first, but then they can suddenly speed up. Why they suddenly go faster instead of rifting at a steady pace has long eluded explanation. But in a new study, researchers suggest that the lithosphere perpetually thins as it rifts, and that after passing a threshold, it snaps like a rope under too much tension, causing plate motions to accelerate.

16 Nov 2016

Mauna Loa's mysterious Ninole Hills were once a rift

Hawaii’s Nīnole Hills, jutting out from Mauna Loa’s southeast flank, are one of the most striking features on the Big Island, though their geologic origins have long been a mystery. A new study looking at gravity anomalies under the hills is revealing that the hills are part of an older rift system that predates the currently active Southwest Rift Zone. The seemingly sudden switch from one rift system to another may provide some clues as to how Mauna Loa grew to be the largest volcano on Earth. “A lot of different ideas have been proposed to explain how the Nīnole Hills were created,” says Jeff Zurek, a geophysicist at Simon Fraser University in Burnaby, British Columbia, and lead author of the new study published in Geophysical Research Letters. It’s been suggested that the hills could be the remnants of an older summit of Mauna Loa, or its predecessor, Mohokea, or that faulting and landslides could have created the unusual topography of the hills, or that they could be from an older, inactive rift system.

11 Aug 2016

Travels in Geology: The King's Highway: The crossroads of ancient Jordan

A trip along the King’s Highway in Jordan today offers breathtaking scenery, world-class geological and archaeological features, and the chance to walk in the footsteps of historic civilizations.

04 Mar 2016

Midwest's hybrid rift formed in three stages

Middle America is not often recognized for its interesting geology, yet it boasts one of the largest and most unusual geologic features in the country: the Midcontinent Rift, which stretches 3,200 kilometers in two arms from Lake Superior to Oklahoma and Alabama. Subsurface imaging of the rift has revealed that it’s not just a rift, it’s also what’s known as a large igneous province, making it a hybrid geologic feature not seen anywhere else in the world. A new modeling study is offering a more complete story of how the Midcontinent Rift evolved, in three stages. 
 
23 Dec 2015