Earthquakes lie among the most serious disasters in the world today. There have been many cases of this natural phenomenon that have caused massive destruction. The Tsunami disaster is a perfect example of the catastrophe. The earthquake caused a terrible demolition, and a lot of people lost their lives. In this paper, I will lay a detailed focus on the Okhotsk Sea earthquake which hit Moscow in 2013.
Okhotsk Sea earthquake is one of the strongest tremblers that posed a puzzle to the seismologists. Despite the fact that it is known to be one of the powerful earthquakes, it did not cause any damage. It swept from one end of Russia to another without hurting anyone. Many people feared that it would result in a lot of damages, and some ran away from offices and homes.
The earthquake that hit Russia had a lot of strength because the shaking was felt quite far away, in particular, about 4400 miles to the west. The nearest village from the location where Okhotsk Sea earthquake occurred was 130 km away. The coming catastrophe even promoted emergency agencies to issue warnings, but they were later removed since the tremors did not cause any damage. The Okhotsk Sea earthquake occurred in Kuril –Kamchatka region that is well known for seismic activities in the area (Ghose, 2013).
The deep section that held the storm is famous for hosting a series of previous tremblers. Some of the other large earthquakes took place in July 2008 (630km depth) and November 2008 (490km depth). Seismologists argued that the depth of the earthquake made it possible for the tremors to be felt many kilometers away. Many residents were shocked as they had to leave their buildings. A quick evacuation of school children was also led.
Tremors are not a common phenomenon in Moscow; the only record of such an incidence took place in 1977. The effects of the Okhotsk Sea earthquake were so intense since the metrological experts reported that shaking could be felt even in Siberia. The zones of the earth subduction were very deep and, therefore, the depth of the plates was also known to increase with it (Stephens, 2013). The earthquakes on the Pacific side are shallower compared to the one at Okhotsk Sea. It did not just take place at the surface, but it happened at the largest depth in the Pacific plate. The high depth of Okhotsk Sea earthquake explains the reason no tsunami appeared even though the trembler was very strong (Stephens, 2013). The deep earthquakes never produce tsunamis unlike the shallow ones.
The Okhotsk Sea earthquake features in the record as one of the tremblers that have had the largest depth in the world (Stephens, 2013). It occurred in May 2013 and left the experts with more queries on what could have led to the enormous depth of the earthquakes. These acts of nature have been common phenomena but the Okhotsk Sea earthquake, was not a usual one. Seismologist struggled as they attempted to explain what could have happened and what caused the trembler. Various studies that were carried out on this issue revealed that the Okhotsk Sea earthquake had a huge magnitude.
The Okhotsk Sea earthquake struck more than six hundred kilometers making it the first trembler to penetrate with such a huge depth (Ghose, 2013). It had a seismic moment that was greater than the 1994 earthquake in Bolivia. According to Will Englund, the earthquakes that have a large depth such as the Okhotsk Sea earthquake always occur in the transition region (Englund, 2013). The region of the mantle is found on the top side and the one on the bottom side (Stephens, 2013).
The deep earthquakes occur due to stress in the slabs deeply subdued in a region where the crust of the earth dives below a different plate. These types vary from others because they are not accompanied by strong trembling of the ground. They do not cause a lot of harm when compared to other types of earthquakes. However, they are of great scientific importance (Ghose, 2013). These earthquakes happen in a very mysterious way. Scientists have always wondered how a rock can slide at such a high speed as a result of pressure from a rock that is underlying.
The Okhotsk Sea earthquake is known to have produced energy that resulted in great vibrations. It is the only one of this kind because the rapture area of the earthquake was also large, approximately 180 km (Ghose, 2013). It was accompanied by a high speed of about four kilometers per second. The speed was significantly higher compared to earthquakes that occur on the surface (Stephens, 2013).
According to Tim Stephens, deep earthquakes are known to occur between 400 -700km below the surface. The earthquake took place at a depth of more than six hundred kilometers, and this is one of the issues that make it a mystery (Stephens, 2013). The energy release associated with the earthquake was almost three times higher compared to the Bolivia earthquake (Ghose, 2013). The same energy can be compared to the one that can be produced by a blast of a TNT measuring 35 megaton.
The scientists based the research on Okhotsk Sea earthquake from the Bolivia trembler since it was one of the deepest in the world (Ghose, 2013). According to Tim Stephens, the Okhotsk Sea earthquake resembled a shallow event accompanied by a slow rupture (Stephens, 2013). It seemed to have occurred due to a unique form of faulting that had some deformation. The Okhotsk Sea earthquake was not just a slippage or a rapid breaking of the rocks as it is the case with other such phenomena.
The researchers compared the Okhotsk Sea earthquake with the Bolivia one and made a comparison of the variations of the age and the temperatures of the slab that was subducted. According to Tim Stephens, the temperatures attributable to the Okhotsk Sea earthquake are a bit lower than the temperatures in the Bolivia case (Stephens, 2013). The Okhotsk Pacific plate is very cold when compared to the temperatures of slab where the Bolivia earthquake took place (Englund, 2013).
The high temperatures that surrounded the Bolivia earthquake explain the bigger deformation of the rock as well as the ductile process (Englund, 2013). In the Okhotsk Sea case, the earthquake could have occurred due to a fault of the oceanic plate that bent into Kuril Kamchatka zone (Stephens, 2013). However, the scientists have not explained the mechanism involved in the initiation of a shear fracture in conditions of massive pressure that is confining. According to Tim Stephens, the fluid that is present can lubricate the fault. However, if that was the case, all the fluids could come out of the slabs prior to attaining that depth (Englund, 2013).
In case a fault makes a little slip, the friction has the capability of melting the rock, thus providing fluid. The melting could have appeared in a runaway thermal effect (Stephens, 2013). The researchers also argued that the transformation process of some minerals could have been the result of the initiation of the process (Ghose, 2013). The researchers attributed the mineral transformation process to the Olivine rock found in such regions due to the massive pressure in the area. Olivine rock is known to transform into spinel and shear waves, and these are the main waves that are normally produced by earthquakes (Ghose, 2013).
The waves produced were propagating at a very fast speed, and they could easily radiate the surges that were recorded (Englund, 2013). They had similar properties with the waves associated with deep earthquakes. For example, the transformation of Olivine is an irreversible reaction and, therefore, no aftershocks can occur. The same feature is attributed to deep earthquakes. Some researchers believe that the same physics could be applied to the Okhotsk Sea earthquake. Unfortunately, others argue that there was no evidence of such in the Okhotsk Sea earthquake (Englund, 2013)
Okhotsk Sea earthquake is known to be the greatest and deepest trembler that has ever occurred in the history. Its strength was about three times higher than the earthquake that occurred in Bolivia. It is posed as a mystery to scientists. Despite its massive strength, the earthquake did not cause any damage as one would expect. The seismologists have tried to come up with various explanations for the phenomenon as they tried to explain what happened. The earthquake swept all corners of Moscow and left everything still.