All posts tagged: Plate Tectonics

Antarctic seismic data points to an ancient structure circling Earth’s core

Antarctic seismic data points to an ancient structure circling Earth’s core

Published by Jenni Sidey

A layer only a few to a few dozen kilometers thick may be draped across the boundary between Earth’s core and mantle, and researchers say it likely consists of ancient ocean floor pushed deep underground over geologic time. That is the picture emerging from a study led by The University of Alabama, published in Science Advances, which used seismic data from Antarctica to probe a vast stretch of the Southern Hemisphere nearly 2,000 miles below the surface. The team found evidence that ultralow velocity zones, or ULVZs, are not just isolated patches in a few places. Instead, they may be widespread along the core-mantle boundary. These zones slow seismic waves and appear denser than the surrounding deep mantle. The researchers argue that the best explanation is old oceanic material that sank through subduction, then spread and accumulated along the bottom of the mantle. “Seismic investigations, such as ours, provide the highest resolution imaging of the interior structure of our planet, and we are finding that this structure is vastly more complicated than once thought,” said …

Earth’s tectonic plates were already shifting 3.5 billion years ago

Earth’s tectonic plates were already shifting 3.5 billion years ago

Published by Jenni Sidey

The rocks didn’t look like much from the outside. Scattered across a remote stretch of western Australia called North Pole Dome, they were ancient, weathered, and largely ignored for the better part of Earth’s history. But locked inside those formations, in tiny magnetic minerals no larger than grains of dust, was a record of something that geologists have argued about for decades. Earth’s outer shell was moving. And it was doing so 3.5 billion years ago. A study published in Science, led by researchers from Harvard’s Department of Earth and Planetary Sciences, presents what the authors describe as the oldest direct evidence yet of plate movement. The work doesn’t end a long-running debate about when modern plate tectonics began. However, it does push the story much deeper into the planet’s past than many scientists expected. A Two-Year Hunt Inside Ancient Stone The researchers focused on the Pilbara Craton, a fragment of early Earth in western Australia that ranks among the best-preserved pieces of Archean rock on the planet. These formations date to a time when …

Astonishing study claims Spain and Portugal are ‘rotating’ and moving | World | News

Astonishing study claims Spain and Portugal are ‘rotating’ and moving | World | News

Published by Sam Flores

The Iberian Peninsula is moving, scientists say (Image: Getty Images) Spain and Portugal are “rotating” and “moving northwards,” according to a new study. Scientists say the two European countries are slowly undergoing a “clockwise rotation” on their axis. Previously the Iberian Peninsula had been considered by geologists as an “immobile block”. But a new study has found that it is moving northward and heading towards the Eurasian tectonic plate. And while the change, around four to six millimetres a year, isn’t something that will have an impact on daily life, it has changed the way geologists understand the tectonics of Europe, reports Executive. Read more: Huge dementia breakthrough as scientists make bombshell ‘superagers’ discovery Portugal is reportedly moving clockwise (Image: Getty) It comes as scientists have previously concluded that both plates on either side of the Gibraltar Strait are moving, theorising that they will one day close, joining Africa and Europe once more. Researcher Asier Madarieta from the University of the Basque Country, said: “Every year the Eurasian and African plates are moving 4–6 mm …