Taxonomy term

kate s. zalzal

Zircons hold clues to early Earth

Not much is known about the first 500 million years of Earth’s history, between 4.5 billion and 4 billion years ago. We know the interior of the planet was hotter than it is today, and that Earth’s surface experienced intense meteorite bombardment, which left the surface pocked with magma-filled craters. But with no rock record available from this period — the oldest rocks are 4.04 billion years old — scientists must look to the composition of tiny grains of the mineral zircon to provide clues about Earth during the Hadean Eon. But where did the zircons come from?

09 Sep 2016

Benchmarks: September 8, 1900: Massive hurricane strikes Galveston, Texas

Everyone said it couldn’t happen. City leaders saw no need for an expensive seawall, trusting local meteorologist Isaac Cline when he claimed that it was “impossible for any cyclone to ... materially injure the city.” And so, on the morning of Sept. 8, 1900, when the skies over Galveston, Texas, darkened with rain and the winds blew strong, residents of this booming barrier island community believed their city could weather any storm. By the next morning, the city lay in ruin, blasted by a Category-4 hurricane that killed an estimated 10,000 people — a quarter of the island’s population — and more than the combined death tolls of all other landfalling U.S. hurricanes since.

08 Sep 2016

Snake River eruption history offers glimpse into Yellowstone hot spot dynamics

About 8 million years ago, what is now the Snake River Plain of southern Idaho ripped open in a catastrophic super-eruption that spewed roughly 1,900 cubic kilometers of lava and ash across thousands of square kilometers. New research, based on field studies and geochemical analyses of rocks collected on the plain, shows that this eruption was just one of many massive mid-Miocene volcanic events arising from the Yellowstone hot spot. The work also provides a window into the complex and evolving mantle-crust interactions that have occurred as the North American Plate has moved westward over the hot spot.

30 Jul 2016