The earthquake and tsunami that struck the nation of Japan in March of 2011 were devastating, not only to the people of Japan but to the economy and the many infrastructures in the country of Japan. The earthquake was the largest ever to hit Japan. The 9.0 magnitude earthquake and tsunami caused 20,000 deaths and 2,500 missing people. There was a massive loss and damage to buildings, with 1,000,000 buildings either damaged, abandoned, or destroyed. The direct financial damage was estimated to be about 16.9 trillion yen (about 199 billion dollars). 

 

This disaster still is the costliest natural disaster in the world. The methods that scientists used were to see the seismic velocity and the tremor activity of the earthquakes. They observed vigorous, energetic workouts that caused such a devastating earthquake. The sea-floor displacements were so large that they went across 60 to 80 miles and occurred near Sea-floor displacements were large and 60 to 80 miles and occurred near a subduction trench. 

 

 On March 11, 2011, the nation of Japan was hit by a devastating earthquake and tsunami combo that caused significant and irreversible damage for many years to come. A magnitude 9.0 earthquake occurred in the international waters of the Western Pacific Ocean. As a result, the earthquake induced a massive tsunami. The 9.0 magnitude earthquake was the third-highest recorded globally, after the 9.2 magnitude earthquake that hit Alaska in 1964 and the 9.5 magnitude that hit Chile in 1960. The day after the earthquake occurred, the Japanese government officially named the quake "The Eastern Japan Great Earthquake Disaster." Only the northeastern part of Japan was hit by the quake. Yet, this earthquake caused massive economic losses, destructive property damages, and numerous human casualties, among other losses.

 

The economic impact of the earthquake and tsunami was also catastrophic to the nation of Japan. In the first year of the earthquake and the tsunami events, an estimated 16.9 trillion yen worth of damage was caused. In 2013, it was the costliest natural disaster on record. 2.9 trillion yen was spent on insurance payouts, and 17.7 trillion yen was spent on response and recovery budgets by the Japanese government. This disaster-damaged Japan on a physical level and an economic level. A massive number of communities, businesses, and financial sectors in Japan became vulnerable by the end of this tragic event.

 

Several days after the earthquake occurred, up to 190,000 buildings were damaged, among which 45,700 were destroyed. The total loss of buildings was over 1,000,000, either damaged, destroyed, or abandoned. There were millions of tons of debris and rubble produced due to the earthquake in Japan and the tsunami disaster. Several nuclear power plants and thermal power plants were heavily damaged in this disaster. The power supply of Tokyo Electric companies was heavily reduced, causing power outages and blackouts for 4.4 million families in eastern Japan. The number of human lives lost was massive. The human lives lost just off the Tohoku coast counted on September 30, 2011, was about 15,815, and 3,966 human lives were missing. The tsunami deaths of Tohoku were even worse, with 18,658 dead and missing; it is one of the deadliest tsunamis ever to hit Japan. 

 

An earthquake that the people of Japan did not anticipate struck off the shore of Honshu, Japan. A shear sliding fault, where the Pacific plate thrust below Japan, lasted 150 seconds. The sliding shifted up the coast, eastward of Japan up to 5 miles. It lifted the seafloor by 5 miles over 15,000 km, an area compared to the whole state of Connecticut. The sea-floor displacement was so sudden that it generated an immense tsunami that swept across the coastline by the islands of Honshu and Hokkaido. Sea-floor displacements were large, across 60 to 80 miles, and occurred near a subduction trench. The largest that was ever measured for an earthquake. The total strain of energy was the equivalent of 100 megaton explosions. This was released during the sliding.

 

Recent studies have shown the passing of seismic waves from large earthquakes. These earthquakes can trigger seismicity at large distances ranging from small to non-impulsive seismic signals known as tremors. To detect earthquakes and tremors that were potentially triggered during the passing waves of the large 2011 Japan earthquake. Data from the Bulletin of the International Seismological Center and waveforms from multiple seismic networks were used to detect tremors and earthquakes potentially triggered during the passing waves of this large earthquake. Gonzalez-Huizar and the rest of his scientists searched the ISC catalog for earthquakes within a time window of 30 minutes after the arrival of the surface waves, which accounts for the event of the maximum wave displacement.

 

Scientists observed the changes in the seismic velocity of the earthquakes in Japan by using scattered waves retrieved by ambient seismic noise. To estimate the autocorrelation of ambient noise records caused by earthquakes, Minato and the rest of the scientists applied running absolute amplitude normalization to suppress tremors. They observed the Japan earthquake at a specific window and saw how the normalization affects the weighting range to suppress strong amplitudes

 

The earthquake and tsunami in Japan in March 2011 was a tragic event that affected human lives, building properties, and the economic integrity of the Japanese nation. To better understand the cause of the earthquakes, many scientists observed the seismic activity, tremors, and teleseismic waves. It wasn't surprising that there were many seismic stations near Japan due to the damage caused by the 9.0 magnitude earthquake. But it was astonishing to see that there were many seismic stations in various places worldwide. The velocity occurring deep in the crust of the earthquake shows ground motion is an essential factor of a significant earthquake.