May 27, 2017

Geologists find very hot lava flowed on Earth in recent times

A new study shows that some komatiites — cooled lava that flowed on Earth as long as 2.5 billion years ago — may be much younger and hotter than geologists previously thought.

The discovery: Geologists recently found evidence of 89 million-year-old komatiites in Costa Rica. "These are very, very young," said Esteban Gazel, author of the study, told Popular Science. "In geologic terms, 89 million years ago is like it happened a second ago."

Why it's so startling: Most komatiites originated during the Archean age, between 4 billion and 2.5 billion years ago, when Earth's interior was so hot that some lava flows were white instead of red. Since then, Earth's mantle has cooled by about 500 degrees Fahrenheit, but the discovery of these newer komatiites suggest deeper areas of the planet have maintained the hot temperatures of the Archean period.

Why it matters: "What is really fascinating about this study is that we show that the planet is still capable of producing lavas as hot as during the Archean time period," Gazel said in a statement. "Based on our results... we think that mantle plumes are 'tapping' a deep, hot region of the mantle that hasn't cooled very much since the Archean. We think that this region is probably being sustained by heat from the crystallizing core of the planet."

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Updates: George Floyd protests continue for 8th day

Police officers wearing riot gear push back demonstrators outside of the White House on Monday. Photo: Jose Luis Magana/AFP via Getty Images

Protests over the death of George Floyd and other police-related killings of black people continued Tuesday across the U.S. for the eighth consecutive day, prompting a federal response from the National Guard, Immigration and Customs Enforcement and Customs and Border Protection.

The latest: The National Park Service said in a statement Tuesday that while it "is committed to the peaceful expression of First Amendment rights," it "cannot tolerate violence to citizens or officers or damage to our nation’s resources that we are entrusted to protect."

American carnage

Protesters race up a hill to avoid tear gas in Philadelphia, June 1. Photo: Mark Makela/Getty Images

The list of victims has swiftly grown since George Floyd died in police custody just eight days ago.

The big picture: Protests against police brutality have turned into a showcase of police brutality, with tear gas and rubber bullets deployed against crowds. The police have the arsenals at their disposal, but we're also seeing law enforcement officers becoming targets.

McConnell blocks resolution condemning Trump's actions against peaceful protesters

Senate Majority Leader Mitch McConnell (R-Ky.) blocked a resolution introduced by Minority Leader Chuck Schumer (D-N.Y.) on Tuesday that would have condemned the use of tear gas and rubber bullets against peaceful protesters outside the White House on Monday in order to allow President Trump to walk to St. John's Church.

What they're saying: "Justice for black Americans in the face of unjust violence, and peace for our country in the face of looting, riots, and domestic terror. Those are the two issues Americans want addressed," McConnell said on the Senate floor.