Oddly Behaving Blobs Beneath Earth's Surface Finally Explained

[Judi Lynn]

By Dan Robitzski, Staff Writer | November 28, 2017 09:18am ET

The boundary between the Earth's outermost layer, the crust, and the underlying mantle is speckled with mysterious, blob-like regions. Scientists have long known about these odd pockets, which are called ultralow-velocity zones. They slow down the seismic waves caused by earthquakes and may be the culprit for deep mantle plumes, which can lead to volcanic hotspots like those that created Yellowstone National Park or the Hawai'ian Islands.

Researchers have postulated a number of explanations for what these ultralow-velocity zones are made of and how they're formed. But none of those ideas quite fit the data, especially given how differently some of the zones behave from one another.

Now, a team of scientists is proposing a new model that includes not only a feasible composition but also a plausible origin story for ultralow-velocity zones. Even so, the scientists behind the study concede that there could be different or even individual variations for other types of these mysterious, subterranean regions beyond their new findings. [7 Ways the Earth Changes in the Blink of an Eye]

The core-mantle boundary in which ultralow-velocity zones reside is incredibly hot and pressurized — enough so that when the tectonic plates push beneath the crust via subduction, they are melted down and recycled into the mantle. Pressure levels reach 900,000 times what we experience at sea level and temperatures can exceed 3,000 degrees Fahrenheit (1,649 degrees Celsius).

More:
https://www.livescience.com/61036-mysterious-blobs-beneath-earth.html?utm_source=notification

[C_U_L8R]

1. Trump must be golfing, again.

[klook]

2. Ah, so it's not 400-lb. guys on beds in their parents' basements hacking the DNC email servers! (nt)

[byronius]

3. We know so little about what's over our head and under our feet.

Great post.

[MFM008]

4. Oddly behaving blobs

On top as well.

[eppur_se_muova]

5. "Hydrogen-bearing iron peroxide" ?? Um um um ...

I wish the figures weren't behind a paywall. I'd like to see what actual stuctures they were using in their DFT calculation. Granted, this is at extremely high pressure, where chemical "intuition" may break down pretty thoroughly. But having hydrogen present without O-H bonding seems a little farfetched.