Mantle Rock Behind Yellowstone’s Supereruptions Extends To Northern California

Victor Camp has spent a lifetime studying volcanic eruptions all over the world, starting in Saudi Arabia, then Iran, and eventually the Pacific Northwest. The geology lecturer finds mantle plumes that feed the largest of these eruptions fascinating, because of their massive size and the impact they can have on our environment.

Over the past two years, this abiding interest helped him connect the dots and discover that the mantle source rock that rises upward from beneath Yellowstone National Park to feed its periodic supereruptions also spreads out west all the way to Northern California and Oregon.

On its westward journey, it acts as the catalyst for fairly young—meaning less than 2 million years old—volcanic eruptions at places such as Craters of the Moon National Monument and Preserve in Idaho, before reaching Medicine Lake Volcano in the northeastern tip of California, close to the Oregon border.

The mantle rock spreads laterally through narrow flow-line channels well below the earth’s crust for over 500 miles, bifurcating twice: once as it leaves Yellowstone and again as it reaches the California-Oregon border. These lines end at Medicine Lake, an active volcano near Mount Shasta, and at Newberry Volcano, an active volcano about 20 miles south of Bend, Ore.

This discovery is significant because it reveals how mantle plumes similar to the one beneath Yellowstone behave as they feed the majority of the world’s largest volcanic eruptions of basaltic lava, including the ones in Hawaii.

“Since the plume is not controlled by plate tectonics, it can rise and emerge anywhere on earth, depending on where it manages to break through the earth’s surface,” Camp said. “So, knowing this will help us understand supereruptions that have occurred before, and those that will occur in the future.”

The results of his self-funded study were published in the journal Geology in May.

Mantle plumes are composed of very hot, low-density mantle rock. Mantle is one of three major layers of planet earth—we live on the earth’s crust, the thinnest layer, and mantle is the second denser layer that extends from about 100 kilometers (62 miles) below the earth’s surface all the way down to about 2,700 kilometers (about 1,680 miles), and further down is the core of the earth comprised mostly of iron mixed with a few other elements.

Mantle plumes are technically mantle rock, but because they are hotter and more buoyant than surrounding mantle they rise in a plume-like form. When the Yellowstone plume first reached the base level of the North American tectonic plate, it was blocked by the rigidity of the cold plate base which acted as a barrier. At this depth of about 100 kilometers, the plume began to decompress and melt, while simultaneously spreading laterally to the west.

The mantle rock that Camp traced to California took many millions of years to move out west. What’s interesting is that the source of the mantle rock under Yellowstone today originated at the core-mantle boundary geographically centered near present-day San Diego, but very deep beneath the earth’s surface we reside on—and took a circuitous route through different regions of the mantle before it rose up underneath the Yellowstone volcano.

Camp sourced seismic tomography images, similar to X-rays and CT-scans (computerized tomography scans), that show how the mantle plume ascended, and he analyzed field data as well as published chemistry and age data on volcanic rocks at the surface, to demonstrate its westward flow.

Early Seismic Waves Hold The Clue To The Power Of The Main Temblor

Scientists will be able to predict earthquake magnitudes earlier than ever before thanks to new research by Marine Denolle, assistant professor in the Department of Earth and Planetary Sciences (EPS).

“For large-strike slip earthquakes like those that occur on the San Andreas Fault, which are likely to rupture for about 50 seconds, we would be able to predict the final magnitudes 2 to 5 seconds after getting the first seismic wave,” said Denolle, senior author of the study that appeared recently in Geophysical Research Letters.

Denolle shares authorship with Philippe Danré, the first author and former EPS visiting master’s student; Jiuxun Yin, a Ph.D. candidate in the Graduate School of Arts and Sciences; and Brad Lipovsky, an EPS researcher. The team also proved that the activity of earthquakes is actually organized, not chaotic as scientists had previously believed.

“Our research, which is technically rather simple, provides answers relevant not only to earthquake dynamics, but to prediction of earthquake behavior before the earthquake ends,” said Denolle. While there is still no way to predict quakes before they begin, current detection systems consist of a series of sensors that transmit signals to determine the location and magnitude once rapid shaking occurs.

Denolle and her team used data products and created numerical models to predict an earthquake’s final magnitude 10 to 15 seconds faster than today’s best algorithms—seconds that could provide enough time for people to exit a building or for officials to stop traffic before shaking starts.

The team began by examining patterns of seismic signals—transient waveforms that radiate from the first rupture in a fault, a thin seam of crushed rock separating two blocks of the earth’s crust. An earthquake occurs when the blocks break free. Scientists read these waves using an underground instrument called a seismometer that translates motions into a graph called a seismogram. “Seismograms give us information about what happened on the fault at the place where the earthquake occurred,” said Denolle.

Denolle and her team combined previous seismograms, which recorded changes in the waves over time as they traveled between the seismometer and the fault. This data product, known as “source time function,” provides a more accurate read on the waves from the source over long distances.

Denolle and her team examined a catalog of source time functions from earthquakes around the globe between 1990 and 2017. They discovered that large earthquakes are actually composed of a series of subevents, smaller events whose size is nearly proportional to the size of the main one. The team concluded that they could predict the final size of an earthquake based on the size of the first few subevents.

“The self-organization of earthquake ruptures is well-explained by heterogeneity on the fault, and our current knowledge of earthquake physics can explain our observations,” said Denolle.

The researchers hope their work will continue to evolve and can one day help improve the algorithms for early warnings of earthquake. To do this, they will work on extracting more accurate high-frequency signals from earthquakes to understand more about their dynamics.

“Eventually, we would hope that the study can provide some guidelines for proper modeling of large earthquakes, and serve as a tool for earthquake early warning, especially for regions expecting large earthquakes, like the Pacific Coast and Japan,” said Denolle.

6.0 Earthquake Strikes Taiwan’s Yilan, Whole Country Feels Shock Waves

A magnitude 6.0 earthquake struck northeastern Taiwan’s Yilan County at 5:28 a.m. this morning (Aug. 8), according to the Central Weather Bureau (CWB).

The epicenter of the temblor was 36.5 kilometers southeast of Yilan County Hall at a depth of 22.5 kilometers, based on CWB data.

The quake’s intensity, which gauges the actual effect of the tremor, registered a 6 in Yilan County and a 4 in Hualien County, New Taipei City, Taipei City, Hsinchu County, Taoyuan City, and Taichung City. An intensity level of 3 was felt in Nantou County, Keelung City, Miaoli County, Hsinchu City, Changhua County, and Yunlin County.

An intensity level of 2 was recorded in Chiayi County, Chiayi City, and Tainan City. An intensity level of 1 was reported in Taitung County, Kaohsiung City, Pingtung County, and Penghu County.

Located along the so-called Pacific Ring of Fire, Taiwan uses an intensity scale of 1 to 7, which gauges the degree to which a quake is felt in a specific location.

Reports are filtering in of products falling off of store shelves and ceiling tiles falling in Yilan County. A woman in Taipei was reported to be in critical condition after her wardrobe fell on her during the initial 6.0 quake.

The MRT in Taipei is already running normally and Taiwan’s High Speed Rail is expected to resume normal operations shortly. Taiwan Railways Administration (TRA) train tracks are currently being inspected in Yilan City and Nan’ao, Taiwan, but the rest of the TRA’s trains are expected to operate normally.

CWB officials are warning the public to beware of aftershocks.

6.3-Magnitude Earthquake Struck Off The Coast Of Japan Near Fukushima

The earthquake rattled the same region of Japan where an earthquake triggered a nuclear power plant disaster in 2011.

Graphic shows large earthquake logo over broken earth and Richter scale reading

A 6.3-magnitude earthquake struck offshore of Japan near Fukushima on Sunday. People reported feeling the quake in the capital, Tokyo, approximately 250 km (155 miles) away.

There were no were immediate reports of damage, and no tsunami alert was issued.

The epicenter of the earthquake, which struck at 7:23 p.m. local time, was off the coast of Fukushima prefecture and measured at a depth of 50km, the Japan Meteorological Agency said.

Public broadcaster NHK TV reported that utility companies were checking on the nuclear reactors in the area.

No abnormalities were found at nuclear power plants in the region, including both Fukushima Daiichi and Daini, according to their operators, the Mainichi reported.

In 2011, Fukushima was hit by a 9.0-magnitude earthquake, which sparked a monster tsunami causing three nuclear meltdown, hydrogen explosions and radioactive contamination.

Magnitude 7.3 Quake Hits Laiwui, Indonesia, No Tsunami

A 7.3-magnitude earthquake has jolted South Halmahera regency in North Maluku. According to the United States Geological Survey (USGS), the quake occurred at 4:10 p.m. Jakarta time or 6:10 p.m. local time, 102 kilometers north-northeast of Laiwui in South Halmahera, at a depth of 10 kilometers.

The Meteorology, Climatology and Geophysics Agency (BMKG) said there was no tsunami potential detected because of the earthquake. It has also recorded several aftershocks. Meanwhile, the BMKG reported at 5:04 p.m. Jakarta time, there was a 5.2-magnitude earthquake with an epicenter at 61 kilometers southwestern off Biak Numfor regency in Papua.

Based on official information from the South Halmahera Disaster Mitigation Agency (BPBD), the quake was mostly felt in the regency for two to five seconds, prompting people to panic and rush out of their homes.

 

Tsunami Threat Expires Following 6.9-Magnitude Earthquake In Indonesia

A powerful earthquake struck under the water surrounding Indonesia, prompting a tsunami warning which encompasses hundreds of the country’s 17,000 islands.

Indonesian officials issued the tsunami warning for coastal areas after the earthquake occurred in the Molucca Sea, which is located between the islands of Sulawesi and Maluku. The warning has since expired and there is no tsunami threat at this time.

The United States Geological Survey stated that the earthquake had a magnitude of 6.9, while officials from Indonesia stated that the earthquake was slightly stronger with a magnitude of 7.1.

The tsunami warning was in effect for the eastern coast of North Sulawesi and the western coast of North Maluku. Latest projections are for a tsunami of 0.5 of a meter (1.5 feet) or less.

The earthquake rumbled at 10:08 p.m. local time (11:08 a.m. EDT) on Sunday.

There is potential for heavy-intensity rainfall with lightning, thunder, and gusty winds until 3:30 a.m. local time (WIB).

The earthquake caused panic in the city of Ternate on the island chain of Maluku.

“Showers and thunderstorms will continue to be around central Indonesia through Monday,” according to AccuWeather Meteorologist Maura Kelly.

7,1 Magnitude Earthquake Hits Near Ridgecrest In Southern California

A 7.1-magnitude earthquake rocked Southern California on Friday night — the second temblor to hit near Ridgecrest in less than two days.

The latest earthquake occurred 11 miles northeast of Ridgecrest, according to the US Geological Survey. It rocked buildings and cracked foundations, sending jittery residents out on the streets.

It comes a day after a 6.4-magnitude earthquake centered near Ridgecrest rattled the state Thursday. That earthquake has produced more than 1,400 aftershocks, scientists said.

Multiple fires and injuries have been reported in Ridgecrest — about 150 miles from Los Angeles — after Friday’s earthquake, Kern County spokeswoman Megan Person said. The county has activated an emergency operations center, the fire department tweeted.

The San Bernardino County Fire Department said it has received multiple reports of damage from northwest communities in the county.

“Homes shifted, foundation cracks, retaining walls down,” the department said. “One injury (minor) with firefighters treating patient.”

Localized power outages in LA

In central Los Angeles, Friday’s earthquake felt stronger than the one a day earlier, making buildings rock back and forth forcefully. Donald Castle, who lives in Porterville west of Ridgecrest, said his house shook for between 20 and 25 seconds.

“It was more of a shake than what we had on the Fourth. It lasted longer and was more rolling,” he said.

Public safety units are being deployed throughout the city ” to ensure safety and inspect infrastructure,” Los Angeles Mayor Eric Garcetti said.

The Los Angeles Fire Department said there were reports of wires down and localized power outages in some parts of the city. Fire crews are still surveying the city, it said, but no major damage to infrastructure has been identified so far.

The fire department is no longer in Earthquake mode and has determined there are no injuries or significant damage in Los Angeles city, chief Ralph M. Terrazas tweeted.

The shaking was felt in Mexico and Las Vegas

The shaking was felt as far as Mexico, according to the USGS website.

The NBA Summer League game between the New Orleans Pelicans and the New York Knicks in Las Vegas was postponed Friday following reports of the quake. Scoreboards and speakers near the ceiling of the arena shook when the earthquake hit.

Quakes are part of an ongoing system

CalTech seismologist Lucy Jones said Friday both earthquakes are part of an ongoing sequence, of a “very energetic system.”

The latest 7.1 earthquake was the mainshock, while Thursday’s 6.4 magnitude shake was a foreshock, according to Jones. She said Friday’s earthquake was 10 times stronger than the one a day prior.

The 7.1 magnitude shake was five times bigger than Thursday’s, but released 11 times the amount of energy than the 6.4 shake, CNN Meteorologist Brandon Miller said.
Officials are not ruling out that there could be more earthquakes coming.

California Gov. Gavin Newsom said he has activated the state emergency operation center to its highest level.

“The state is coordinating mutual aid to local first responders,” he tweeted Friday night.