BREAKING NEWS: Currently Monitoring High Volume Earthquake Zones

There are five areas I am watching most closely due to the high amount of registered earthquakes, some of which could be defined as ‘swarms’. These areas sit on historic faults or calderas.

Cascadia Subduction Zone

The Cascadia Subduction Zone is capable of producing very large earthquakes if rupture occurs along its entire length. The 1700 Cascadia earthquake occurred along the Cascadia subduction zone on January 26 with an estimated moment magnitude of 8.7 – 9.2. The megathrust earthquake involved the Juan de Fuca Plate that underlies the Pacific Ocean. The earthquake caused a tsunami that struck the coast of Japan with some reports telling of hundreds killed.

Denali Fault

Shortly after midday on November 3, 2002, a magnitude 7.9 earthquake ruptured the Denali Fault in the rugged Alaska Range, about 90 miles south of Fairbanks. Called the Denali Fault earthquake, this shock was the strongest ever recorded in the interior of Alaska. Although comparable in size and type to the quake that devastated San Francisco in 1906, the Denali Fault earthquake caused no deaths and little damage to structures because it struck a sparsely populated region of south-central Alaska.

Long Valley Caldera

In 1872, the magnitude 7.6 Owens Valley earthquake was felt throughout most of California, and a number of moderate (mag. 5 to 6) earthquakes have shaken the Long Valley area during this century. A period of ongoing geologic unrest in the Long Valley area began in 1978, and has since experienced numerous swarms of earthquakes, especially in the southern part of the caldera and the adjacent Sierra Nevada.

Puerto Rico Trench

On October 11, 1918, the island of Puerto Rico was struck by a magnitude 7.5 earthquake, centered approximately 15 kilometers off island’s northwestern coast, in the Mona Passage. In addition to causing widespread destruction across Puerto Rico, the quake generated a medium sized tsunami that produced waves as high as 20 feet along the western coast of the island. The tsunami caused an estimated 4 million dollars in property and other damages to the coastal communities of Puerto Rico. Of the 116 people killed by the earthquake, 40 of those were victims of the tsunami.

1886 Charleston, South Carolina 7.6 Quake

The fifth area I am keeping my eye onOn August 31st 1886, a 7.6 magnitude earthquake struck near Charleston, South Carolina leaving 100 people dead, hundreds of buildings destroying 2,000 buildings in the city and caused $6 million worth of damage ($133 million in modern-day USD).

COMING NEXT: Update on all earth changing events as well as more on the continuing ‘civil disturbance’ occurrences. 

IMPORTANT UPDATE: New Research Shows Quake-Causing Cracks on Pacific Sea Floor

New research published in the journal ‘Science Advances’, has focused their study off the west coast of North America giving seismologists a better understanding of what one scientist describes as “the single greatest geophysical hazard to the continental United States”.

Zach Eilon, a geophysicist at the University of California Santa Barbara, has developed a new method that uses an array of scientific instruments spread across the sea floor to measure shock waves that travel through the planet’s crust. “Because we think this particular phenomenon is strongly related to temperature and to molten rock beneath the Earth, this is a technique that can be applied to volcanoes to get a better sense of their plumbing system,” says Eilon.

Eilon’s research targets the Juan de Fuca plate, which runs several hundred kilometers off the coast between southern British Columbia and northern California and is the youngest and smallest of the planet’s 13 major tectonic plates. The collision zone in this region has the potential to generate massive quakes and destructive tsunamis, which occur when the plates overcome friction and slip past one another, quickly displacing huge amounts of water.

His data suggest the interior of the Juan de Fuca plate is cooler than previously believed, meaning the edge that is being pushed westward below the North American plate is able to bring with it more water. The water acts as a lubricant and increases the likelihood of the slipping that leads to a quake.

Geoff Abers, an earth-sciences professor at Cornell University who co-authored the paper with Eilon, said improvements in sea-floor technology and the sheer number of sensors that were deployed make this project the first time researchers have been able to study an entire tectonic plate in the ocean. “We’re not directly looking at the just earthquake cycles, but we’re looking at the broader, theoretical framework for how the Earth works and getting a much better handle on that,” Abers said.

Thank you for your continued support. We’re now about half way there.

COMING NEXT: WAR AND EARTHQUAKES; IS THERE A CONNECTION

One Of The Most Dangerous Submarine Volcanoes On Earth

One of the most dangerous submarine volcanoes where two tectonic plates separate has been captured in more detail than ever before. A University of Washington study published this week shows how the volcano behaved during its spring 2015 eruption, revealing new clues about the behavior of volcanoes where two ocean plates are moving apart.

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“The new network allowed us to see in incredible detail where the faults are, and which were active during the eruption,” said lead author William Wilcock, a UW professor of oceanography. The new paper in Science is one of three studies published together that provide the first formal analyses of the seismic vibrations, seafloor movements and rock created during an April 2015 eruption off the Oregon coast. “We have a new understanding of the behavior of caldera dynamics that can be applied to other volcanoes all over the world.”

The studies are based on data collected by the Cabled Array, a National Science Foundation-funded project that brings electrical power and internet to the seafloor. The observatory, completed just months before the eruption, provides new tools to understand one of the test sites for understanding Earth’s volcanism.

Axial volcano has had at least three eruptions, that we know of, over the past 20 years,” said Rick Murray, director of the NSF’s Division of Ocean Sciences, which also funded the research. “Instruments used by Ocean Observatories Initiative scientists are giving us new opportunities to understand the inner workings of this volcano, and of the mechanisms that trigger volcanic eruptions in many environments.

“The information will help us predict the behavior of active volcanoes around the globe,” Murray said.

It’s a little-known fact that most of Earth’s volcanism takes place underwater. Axial Volcano rises 0.7 miles off the seafloor some 300 miles off the Pacific Northwest coast, and its peak lies about 0.85 miles below the ocean’s surface. Just as on land, we learn about ocean volcanoes by studying vibrations to see what is happening deep inside as plates separate and magma rushes up to form new crust.

The submarine location has some advantages. Typical ocean crust is just 4 miles (6 km) thick, roughly five times thinner than the crust that lies below land-based volcanoes. The magma chamber is not buried as deeply, and the hard rock of ocean crust generates crisper seismic images.

“One of the advantages we have with seafloor volcanoes is we really know very well where the magma chamber is,” Wilcock said.
“The challenge in the oceans has always been to get good observations of the eruption itself.”

All that changed when the Cabled Array was installed and instruments were turned on. Analysis of vibrations leading up to and during the event show an increasing number of small earthquakes, up to thousands a day, in the previous months. The vibrations also show strong tidal triggering, with six times as many earthquakes during low tides as high tides while the volcano approached its eruption.

Once lava emerged, movement began along a newly formed crack, or dike, that sloped downward and outward inside the 2-mile-wide by 5-mile-long caldera.

“There has been a longstanding debate among volcanologists about the orientation of ring faults beneath calderas: Do they slope toward or away from the center of the caldera?” Wilcock said. “We were able to detect small earthquakes and locate them very accurately, and see that they were active while the volcano was inflating.”

The two previous eruptions sent lava south of the volcano’s rectangular crater. This eruption produced lava to the north. The seismic analysis shows that before the eruption, the movement was on the outward-dipping ring fault. Then a new crack or dike formed, initially along the same outward-dipping fault below the eastern wall of the caldera. The outward-sloping fault has been predicted by so-called “sandbox models,” but these are the most detailed observations to confirm that they happen in nature. That crack moved southward along this plane until it hit the northern limit of the previous 2011 eruption.

“In areas that have recently erupted, the stress has been relieved,” Wilcock said. “So the crack stopped going south and then it started going north.” Seismic evidence shows the crack went north along the eastern edge of the caldera, then lava pierced the crust’s surface and erupted inside and then outside the caldera’s northeastern edge.

The dike, or crack, then stepped to the west and followed a line north of the caldera to about 9 miles (15 km) north of the volcano, with thousands of small explosions on the way.

“At the northern end there were two big eruptions and those lasted nearly a month, based on when the explosions were happening and when the magma chamber was deflating,” Wilcock said.

The activity continued throughout May, then lava stopped flowing and the seismic vibrations shut off. Within a month afterward the earthquakes dropped to just 20 per day.

The volcano has not yet started to produce more earthquakes as it gradually rebuilds toward another eruption, which typically happen every decade or so. The observatory centered on Axial Volcano is designed to operate for at least 25 years. “The cabled array offers new opportunities to study volcanism and really learn how these systems work,” Wilcock said. “This is just the beginning.”