BBC News Climate and Science
It has been one of the most powerful earthquakes recorded so far, but it has not brought a fatal tsunami that many people are afraid so far.
When the earthquake hit the East of Russia on Wednesday 11:25 (00:25 BS), the earthquake was raised concerns about the coastal population across the Pacific.
Millions of people evacuated as they returned to the destructive tsunami of Boxing Day in 2004 from the Indian Ocean and Japan 2011.
But today’s tsunami was much less serious despite being slightly damaged.
So what is the cause of the earthquake and tsunami? And why is it not as bad as the first fear?
What is the cause of the mega earthquake?
The KamChatka Peninsula is far away, but there are many earthquakes and volcanoes here, so it is in the “Ring of Fire in the Pacific”.
The upper layer of the earth is divided into a moving section (crustal plate) compared to each other.
“The Ring of Fire in the Pacific” is an arc of this plate extended around the Pacific Ocean. According to the British Geological Survey, 80 %of the world earthquake occurs along the ring.
The Pacific board next to the coast of the Korean peninsula is about 8cm (3 inches) every year, which is only about twice the speed of growing nails, but it depends on the perception standard.
There is contact with another small plate called Okhotsk Micorplate.
Since the Pacific plate is a marine, there is a dark rock and a less concentrated micros also wants to sink underneath.
When the Pacific plate sinks towards the center of the earth, it heats up and starts to melt and effectively disappears.
But this process is not always smooth. Often the plate may be attached when the plate passes, and the finance plate is dragged down.
This friction can be accumulated over thousands of years, but it can be suddenly released in just a few minutes.
This is known as a residency earthquake.
Dr. Stephen Hicks, an environmental earthquake instructor at the University College London, said, “When we think about the earthquake, we can imagine a small point in the epicenter map, but more than hundreds of kilometers of this big earthquake will collapse.
“These vast amounts of slips and defects produce this high earthquake size.”
The largest earthquakes in history, including three strongest in Chile, Alaska, and Sumatra, were the mega trust earthquakes.
And the KAMCHATKA peninsula is easy to have a strong earthquake.
In fact, according to the US geological survey, another high 9.0 earthquake hit less than 30 km (19mi) in today’s earthquake, according to a US geological survey.
Why wasn’t this as bad as the previous tsunami?
This sudden movement can replace the water on the plate, and then moves to the coastline with a tsunami.
In the deep sea, the tsunami can travel more than 500 mph (800 km/h) as fast as a passenger plane.
The distance between the waves is very long and the waves are not very high.
However, as the tsunami enters the shallow water near the ground, it often slows up to about 20-30 mph.
The distance between the waves is shortened and the waves grow in height so that the water walls near the coast can be effective.
But it is never guaranteed that a very strong earthquake cannot be especially inland.
According to authorities, today’s earthquake brought 4m (13 feet) of tsunami waves in eastern Russia.
But they are not close to dozens of waves of Boxing Day in 2004 from the Indian Ocean and Japan 2011.
Lisa McNeill, a professor of Telenic at the University of Southampton, said, “The height of the tsunami is influenced by the seabed shape near the coast and the regional form of the land where it arrives.
“These factors affect how serious the coast is, and how serious it is.”
According to an early report on the US Geological Survey, the earthquake focuses on a narrow depth of about 12.7 km (about 12.9 miles) under the surface of the earth.
This can make the seabed bigger and the tsunami waves can grow, but it is difficult to say clearly immediately after the event.
Dr. Hicks told the BBC NEWS, “It is possible that the tsunami model has been conservative about the earthquake depth.”
“Potentially you can change the earthquake 20 km deeper, which can actually reduce the amplitude of the tsunami wave.”
A better early warning system
Another important factor is the development of the early warning system.
Since there are many earthquakes in the Pacific region, many countries have a tsunami center. They are warned by the public announcement that the population will evacuate.
There was no such system when the boxing day tsunami occurred in 2004. Many people left without time to evacuate.
More than 230,000 people died in 14 countries in the Indian Ocean.
Early warning systems are important because scientists have the ability to predict when earthquakes occur.
The US Geological Survey recorded an earthquake of 7.4 in the same area 10 days ago.
Professor McNil explained that this does not predict the exact time of the future earthquake.
“We can use GPS to measure the current movement, how fast the plate is moving, but when the previous earthquake occurs, you can use this information to predict the probability of earthquake.”
The Earth Physics Survey of the Russian Academy of Sciences (GS RAS) will continue to monitor the region because it can continue aftershocks next month.
