Ancient ocean floor surrounds Earth’s core, seismic imaging reveals

Published

2 years ago

April 17, 2023

admin

A massive ocean floor lurks near Earth’s core. Now, seismic imaging has revealed that it likely surrounds much — if not all — of the core.

This thin, dense layer is lodged roughly 2,000 miles (3,200 kilometers) below Earth’s surface, between the core and the planet’s middle layer, called the mantle. And it might encompass the entire core-mantle boundary, according to a study published April 5 in the journal Science Advances (opens in new tab) .

To study Earth’s interior, seismologists measure earthquake waves that zoom through the planet and then back out to Earth’s surface. By seeing how these waves change after passing through the different structures inside Earth, researchers can create a map of what Earth’s innards look like. Past research identified a handful of isolated pockets of dense ocean crust near the core. These pockets are called ultra-low-velocity-zone structures (ULVZs) because seismic waves travel very slowly through them.

“Only [approximately] 20% of the core-mantle boundary has been previously investigated for ULVZs, which have not been identified in all of these locations,” lead study author Samantha Hansen (opens in new tab) , an associate professor of geological sciences at The University of Alabama, told Live Science in an email. “It is possible that this anomalous material covers the entire core.”

In the new study, scientists placed seismic equipment at 15 stations located across Antarctica and collected data for three years.

Related: 450-mile-wide solid metal ball forms Earth’s innermost core, earthquake waves reveal

This study marks the first time that high-resolution imaging of the core-mantle boundary was made using data from the Southern Hemisphere. The layer itself is razor-thin compared with the core, which is 450 miles (724 km) across, and the mantle, which is roughly 1,800 miles (2,900 km) thick.

“The thickness does vary, depending on location,” Hansen said, with some spots measuring about 3.1 miles (5 km) thick and others 31 miles (50 km) in thickness.

This ancient ocean layer likely developed when Earth’s tectonic plates shifted, causing oceanic material to be carried into the planet’s interior at subduction zones, the areas where two plates collide and force one to dip beneath the other. Over time, “accumulations of subducted oceanic material collect along the core-mantle boundary and are pushed by the slowly flowing rock in the mantle,” according to a statement (opens in new tab) .

Researchers think the newly detected ULVZs are essentially “underground mountains” that allow heat to escape from Earth’s molten core, according to the statement.

“The presence of this layer could buffer heat flow across the core-mantle boundary, which is important because the temperature conditions in this portion of the Earth have been shown to strongly impact the planet’s magnetic field,” Hansen said.RELATED STORIES—’Completely new’ type of magnetic wave found surging through Earth’s core

—Rare primordial gas may be leaking out of Earth’s core

—Earth’s mantle has a gooey layer we never knew about

Chunks of this hidden ocean floor may also get swept up into mantle plumes — hot, upwelling jets of molten rock that fuel volcanic hotspots at the surface, such as in Hawaii, Hansen suggested.

“Further, since mantle plumes are largely controlled by the thermal conditions near the core-mantle boundary, the temperature influence of ULVZs may help dictate where plumes form,” Hansen said.

The research team plans to expand their study by examining data collected from all available seismic stations in Antarctica.

Entertainment

The Wanted star Max George recalls moment he wrote will from hospital bed before heart surgery

Published

3 hours ago

January 13, 2025

admin

The Wanted star Max George recalls moment he wrote will from hospital bed before heart surgery

The Wanted star Max George has told of the moment he wrote his will from a hospital bed, as he was convinced he “was going to die”.

In December, George revealed he had to undergo urgent heart surgery after being diagnosed with a block.

In an interview with The Sun, his first since he underwent the lifesaving surgery, the 36-year-old described the moment when he thought he would die.

He said: “If I could go from being absolutely on top of the world to being told ‘the bottom part of your heart isn’t working’, I kept thinking in my head, ‘Well, what if the top half stops working overnight?'”

“That first night I wrote a will, I thought I was going to die,” the 36-year-old musician added.

On the night of 13 December, George said his heart rate and blood pressure dropped, “I felt like I was dying,” he said.

He had a pacemaker fitted by doctors during the surgery, but the former Strictly Come Dancing star said he made a will on his phone fearing the worst.

Before the surgery, George said his thoughts turned to his partner, British actress Maisie Smith, and his family who he feared he’d leave behind.

He shared updates on social media throughout the process.

While the procedure was complicated by collapsed veins caused by the condition, the surgery was successful and he returned home before Christmas.

He described his pacemaker as “the best Christmas present”.

Tom Parker, who also rose to fame in the 2010s with the boy band along with George, died at the age of 33 after being diagnosed with an inoperable brain tumour.

Entertainment

Former Little Mix star Jesy Nelson announces pregnancy – and it’s twins

Published

3 hours ago

January 13, 2025

admin

Former Little Mix star Jesy Nelson announces pregnancy - and it's twins

Former Little Mix star Jesy Nelson has announced she is pregnant with twins.

The singer, 33, said she was “eating for three now” on her Instagram alongside a polaroid picture of her with Zion Foster, with whom she was reported to have split up last year.

Nelson shared the touching post on Sunday, letting the world know she is set to become a mum for the first time – including two baby emojis next to her message.

The cosy picture shows the pair smiling in a kitchen.

Nelson rose to fame with the girl band Little Mix, which formed on The X Factor in 2011 and earned a string of UK number-one singles.

However, she left in December 2020 after nine years, saying the pressures of being in the group had taken a toll on her mental health.

Nelson has since performed as a solo artist but still had praise for her former bandmates, telling The Graham Norton Show in 2021: “To me they are still the sickest girl band in the world.”

Little Mix continued as a trio after Nelson’s departure in December 2020 before going on hiatus in 2022.

Entertainment

Duchess of Sussex delays release of Netflix series due to LA fires

Published

3 hours ago

January 13, 2025

admin

Duchess of Sussex delays release of Netflix series due to LA fires

The Duchess of Sussex has delayed the release of her new Netflix series due to the devastation caused by the wildfires in LA, the streaming platform has announced.

Meghan’s eight-part series, With Love, will premiere on 4 March instead of 15 January.

“I’m thankful to my partners at Netflix for supporting me in delaying the launch, as we focus on the needs of those impacted by the wildfires in my home state of California,” Meghan said in a statement to Tudum, the official companion site to Netflix.

Harry and Meghan comforted volunteers and handed out food to evacuees during a visit to Pasadena on Friday, where they met with the city’s mayor Victor Gordo and emergency workers tackling the Eaton Fire.

Footage showed the duchess, wearing a blue “LA” baseball cap, and the prince hugging and consoling people who had fled to the Pasadena Convention Center.

Latest on LA fires

They were also seen speaking Doug Goodwin, whose home was destroyed in the wildfires, and also to Jose Andres, founder of World Central Kitchen (WCK) which has been helping feed the public and emergency crews.

A description of the Netflix series on Tudum’s website said: “Produced by Meghan, ‘With Love, Meghan’ blends practical how-to’s and candid conversation with friends, new and old.

“Meghan shares personal tips and tricks, embracing playfulness over perfection, and highlights how easy it can be to create beauty, even in the unexpected.

“She and her guests roll up their sleeves in the kitchen, the garden, and beyond, and invite you to do the same.”

The royals live in Montecito, near Santa Barbara, around 90 miles from Los Angeles.

They are understood to have donated supplies, including clothing and children’s items, to people affected by the disaster.

They released a statement on Thursday urging people to help those affected by the wildfires and to open their homes to those evacuated.