Recently the United States has been rocked by eight earthquakes in quick succession , with three tremors hitting in California and others felt in Oklahoma Alaska, Nebraska and Texas.
The quake was the strongest felt in Southern California for more than four years.
The US Geological Survey said back in 2008 that there was a 99% chance of a huge quake hitting California, which sits on the infamous "Ring of Fire", in the not to distant future. Alaska in the US also sits in the Ring of Fire, which causes many volcano eruptions and earthquakes.
California also lies on the San Andreas fault, where two of the earth’s huge tectonic plates meet.
This has caused many earthquakes over the years, including the recent 5.3 magnitude tremor striking just off the Pacific coast on April 6 near Los Angeles .
Speaking about the most recent California earthquake John Vidale, director of the Southern California Earthquake Centre, told the Los Angeles Times: “It’s right on the edge of being an earthquake that could be dangerous. It’s a reminder that we need to be ready in the future."
He also said he believes that there is a 1-in-20 chance the quake will lead to a larger one in the next few weeks.
Experts predict that an earthquake of 7.8 — three times as powerful as the one that hit in 1994 — would leave at least 50,000 injured and 2,000 dead. The 1994 quake killed 60 and injured 2,000.
What is the Ring of Fire?
The Ring of Fire is a Pacific region home to over 450 volcanoes, including three of the world’s four most active volcanoes – Mount St. Helens in the USA, Mount Fuji in Japan and Mount Pinatubo in the Philippines. It is also sometimes called the circum-Pacific belt.
Around 90% of the world’s earthquakes occur in the Ring of Fire, and 80% of the world’s largest earthquakes.
The 40,0000 kilometre horse-shoe-shaped ring loops from New Zealand to Chile, passing through the coasts of Asia and the Americas on the way.
It stretches along the Pacific Ocean coastlines, where the Pacific Plate grinds against other, smaller tectonic plates that form the Earth’s crust – such as the Philippine Sea plate and the Cocos and Nazca Plates that line the edge of the Pacific Ocean.
The people most at risk from activity in the Ring of Fire are in the US west coast, Chile, Japan and island nations including the Solomon Islands.
These areas are most at risk because they lie on so-called subduction zones – which are boundaries that mark the collision between two of the planet’s tectonic plates.
How was the Ring of Fire formed?
According to Volcano World The Ring of Fire is a ring of volcanoes around the Pacific Ocean that result from subduction of oceanic tectonic plates beneath lighter continental plates.
The area where these tectonic plates meet is called a subduction zone.
What is a subduction zone?
A subduction zone is a place where one plate of lithosphere is shoved under another plate. The lithosphere is the rigid, outermost shell of the Earth, which includes the crust and the uppermost mantle and is divided into tectonic plates.
Most of the Earth’s subduction zones are located around the Pacific ring and the Ring of Fire is a direct result of the movement and collisions of lithospheric plates.
As Volcano World explains, if the overlying plate is a continent, you get a chain of volcanoes such as the Andes or Cascades and if the overlying plate is ocean you get a chain of volcanic islands, such as the Marianas or Aleutians.
Why does the Ring of Fire trigger earthquakes?
The world’s deepest earthquakes happen in subduction zone areas as tectonic plates scrape against each other – and the Ring of Fire has the world’s biggest concentration of subduction zones.
As energy is released from the earth’s molten core, it forces tectonic plates to move and they crash up against each other, causing friction. The friction causes a build-up of energy and when this energy is finally released it causes an earthquake. If this happens at sea it can cause devastating tsunamis.
Tectonic plates usually only move on average a few centimetres each year, but when an earthquake strikes, they speed up massively and can move at several metres per second.
"It takes tens of thousands of years for the energy to build up, but only a matter of seconds for it to be released," said Chinese University of Hong Kong seismologist Yang Hongfeng.
How dangerous is the Ring of Fire?
Well, it’s not called the Ring of Fire for nothing, and volcanic and earthquake activity is almost constant somewhere along the ring so there is some risk attached to living in the regions affected.
Kilauea, which is considered the most active volcano in the world is in the Pacific Ring of Fire. Mount Fuji, the US’s Mount Saint Helens and Mount Rainier in the American North West, as well as Krakatoa in Indonesia and Mauna Loa in Hawaii are all volcanoes that are well known and some that could be very dangerous to the nearby populations.
In August 1883 Krakatoa erupted with devastating effects, expelling huge clouds of gas and ash, generating massive tsunamis, and killing more than 36,000 people.
According to reports at the time the eruption launched ash clouds up to 22 miles high blacking out the sun for three days – and the blasts from the volcano could be heard up to 3,000 miles away.
The debris in the atmosphere was so great that it filtered the amount of sunlight reaching Earth and caused global temperatures to fall by 1.2 Celsius the next year. Temperatures did not get cback to normal five years later in 1888.
Most of the thousands of people who died in the Krakatoa eruption were killed by the huge tsunamis – up to 120 feet high – that were created when the volcano collapsed into the ocean.
In July 2016 Mount Bromo in Indonesia erupted, spewing a column of ash by up to 1,200 meters to the sky.
According to basicplanet.com if Mount Rainier were to erupt the 2.5 million people who live in the area near Seattle and Tacoma would have to evacuate fast.
It also says the snowy cap of the volcano could make the dangers much worse.
In January this year a powerful string of earthquakes hit California, Fiji, Alaska, Japan, Chile, Papua New Guinea, Mexico, Indonesia and Hawaii.
After the spate of recent tremors The Los Angeles Police Department tweeted; ‘#Earthquake follow-up: There have been no reports of earthquake-related damage or injuries within the City of Los Angeles.
‘Our region hasn’t shook like that since 2014. This should serve as a steadfast reminder to act now, get those earthquake preparedness kits ready.’
California has long been known as a period of high seismic activity and the most recent quake of note hit the North San Francisco Bay area in 2014, which killed one person, injured 200 and caused damages estimated to be as high a $1billion.
According to The Express the largest US earthquake ever recorded was a magnitude-9.2 in Alaska in March 1964, causing tidal waves of more than 100 feet high that killed 131 people.
In 2015 incredible timelapse footage captured the powerful eruptions as a massive plume of ash and smoke spewed out of Mexico’s huge Colima volcano – which is part of the Ring of Fire -when it erupted twice within an hour-and-a-half.
In 2017 a magnitude 6.4 earthquake hit off the coast of Hualien in eastern Taiwan, killing 17 and injuring over 200. It also damaged bridges and buckled roads in and around Hualien, a city on the island’s northeastern shores.
An aftershock with the magnitude of 5.7 then hit the already devastated tourist town.
Fourteen of the victims of the quake were in the Yun Men Tsui Ti building in Hualien, a commercial and residential complex that partially collapsed, leaving people trapped inside.
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