Case study: Japan tsunami (HIC) On Friday 11 March at , an earthquake of magnitude nine on the Richter scale. occurred. It was at the point where the Pacific tectonic plate. Fatalities. Injured. On Friday 11 March , an earthquake measuring 9 on the Richter Scale occurred off the north-east coast of Japan, triggering a ten-metre tsunami. A nuclear emergency was declared following explosions at various nuclear plants in the Fukushima area.
The Richter magnitude scale often shortened to Richter scale is the most common standard wzs measurement for earthquakes. It was invented in by Charles F. Richter of the California Institute of Technology as a mathematical device to compare the size of earthquakes. The Richter scale is used to rate the magnitude of an earthquake, that is the amount of energy released during an earthquake.
The Richter scale doesn't measure quake damage see: Mercalli Scale which is dependent wbat a variety of factors including population at the epicentre, terrain, depth, etc. An earthquake in a densely populated area which results in many deaths and considerable damage may japa the same magnitude as a shock in a remote area that does nothing more than frightening the wildlife. Large-magnitude earthquakes that occur beneath the oceans may not even be felt by humans.
The magnitude of an earthquake is determined using information gathered by a seismograph. The Richter magnitude involves measuring the amplitude height of the largest recorded wave at a specific distance from the seismic source. Adjustments are included for the variation in the distance between the various seismographs and the epicentre of the earthquakes. The How much is laser removal of tattoos scale is a base logarithmic scale, meaning that each order of magnitude is 10 times more intensive than the last one.
In other words, a two is 10 times more intense than a one and a three is times greater. In the case of the Richter scale, the increase is in wave amplitude. That is, the wave amplitude in a level 6 earthquake is 10 times greater than in a level 5 earthquake, and the amplitude increases times between a level 7 earthquake and a level 9 earthquake.
The amount of energy released increases In fact, it is to point out that, while it is correct to say that for how to start a home food delivery business increase in 1 in the Richter magnitude there is a waas increase in amplitude of the wave, it is incorrect to say that each increase of 1 in Richter magnitude represents a tenfold increase in the size of the earthquake as is commonly incorrectly stated by the press.
At first, the Richter scale could be applied only to the records from instruments of identical manufacture. Now, instruments are carefully calibrated with respect to each other. Thus, magnitude can be computed from the record of any calibrated seismograph. The Richter Scale has no upper limit.
Recently, another scale called the moment magnitude scale MMS has been devised for more precise study of great earthquakes. Tectonic earthquakes can range in size from magnitudes less than zero, resulting from fault slippage of a few centimetres, to the largest events magnitude greater than 9where fault displacements are on the order of many metres. The size of an earthquake is not only a function of the amount of displacement but also the area of the fault plane that ruptures.
Hence the larger the rupture area, the larger is the earthquake. A magnitude 7 earthquake ruptures a fault area of about km2 or about 50 km long and 20 km wide. Also depth is an important factor influencing earthquake severity.
We know that earthquakes can originate at various whzt within the Earth's solid core. The deeper the earthquake, the more powerful it is, but it is also far less likely to reach the surface. That's why shallow earthquakes are more common and more dangerous, because the shallower an earthquake, the more damage to surface structures it can cause.
The largest earthquakes in historic times have been of magnitude slightly over 9, although there is no limit to the possible magnitude. The most recent large earthquake of magnitude 9. Fortunately most earthquakes are extremely small. A majority of quakes register less than 3 on the Richter scale; these tremors, called micro-earthquakesaren't generally felt by people and are usually recorded only on local seismographs. With every whole point the magnitude rises, the strength of the waves increases tenfold.
Events with magnitudes of about earthquxke. Only a tiny portion of earthquakes 15 or so of the 1. A temblor with a magnitude of 8. The biggest quake in recorded history was the 9. Generally, you won't see much damage from earthquakes that register below 4 on the Richter scale. Toggle navigation. Get earthquake and tsunami alerts. Signup now FREE. If you like this content, help us spread awareness If you like this content, like us on Facebook : or follow us on Twitter!
Richter Scale What is the Richter Scale Scxle Richter magnitude scale often shortened to Richter scale is the most common standard of measurement for earthquakes. Image: What is the Richter Scale. Image: Richter Scale of Earthquake Energy. Image: How is the Richter Scale calculated.
Ln Richter Scale Graphic Representation. Video: Learn about Richter Scale - What is it? Image: Photo from March earthquake in Japan. Useful links.
The earthquake and tsunami
An earthquake measuring on the Richter Scale struck off Japan's north-east coast, about miles (km) from Tokyo at a depth of 20 miles. When? The magnitude earthquake happened at pm (local time) on Friday March 11, Mar 04, · The magnitude earthquake struck at pm. (The early estimate of magnitude was later revised upward.) The epicentre was located some 80 miles ( km) east of the city of Sendai, Miyagi prefecture, and the focus occurred at a depth of miles (about 30 km) below the floor of the western Pacific Ocean. Mar 26, · The March earthquake near Japan – which reached 9 on the Richter scale – was not anticipated for that region of the ocean, geophysicists danhaigh.com: danhaigh.com
On Friday 11 March , an earthquake measuring 9 on the Richter Scale occurred off the north-east coast of Japan, triggering a ten-metre tsunami. A nuclear emergency was declared following explosions at various nuclear plants in the Fukushima area.
Abnormally high levels of radioactive substances were later detected in seawater metres from the plant. Correct on February , the disaster caused 15 fatalities. Another 6 were injured, and 2 missing. Evacuations totalled Due to radiation concerns, Japan halted some food shipments including the suspension of milk and certain vegetables from regions around the plant, following the identification of abnormal radiation levels in the products.
A transport aircraft were also deployed along with search and rescue teams to assist with the relief and recovery. There were registered Australians in Japan at the time of the earthquake, with Australians registered in the affected areas. The event caused extensive damage, with the greatest impact in Sendai city, and the Miyagi and Fukushima prefectures.
Register Log in. Notable aftershocks : 28 March — At 7. Two power plants were knocked offline, cutting power for four million people. The event triggered a brief tsunami warning.