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Scientists believe that the earth is made up of four main layers. The outermost layer being the crust, then the mantle, the outer core and at the centre of the earth the inner core.
The crust is made up of hard rock, mainly granite. The mantle is mainly molten lava on which the crust is floating. The core is mostly iron, with the outer core being liquid and the inner being solid. The mantle is continually moving; this is called convection.
It is also believed that the earth is divided into more than a dozen plates, which are floating on the mantle. This theory is called plate tectonics . The plates often rub together, pull apart, collide or dive under one another. These movements cause earthquakes and also volcanoes.
Where do Earthquakes occur?Earthquakes usually occur in places where two plates meet, called faults. Earthquakes are mostly generated deep within the earth's crust, when the pressure between two plates is too great for them to be held in place. The underground rocks then snap, sending shock waves out in all directions. These are called seismic waves. The underground origin of an earthquake is called the focus. The point at which an earthquake originates on the surface is called the epicentre. Measuring EarthquakesThe Mercalli ScaleThe original scale for measuring the severity of earthquakes was compiled by the Italian Seismologist, Guiseppe Mercalli, in1902. It has gone through a number of revisions since then. The Mercalli Scale relies on how much damage is caused by an earthquake.
Currently it runs as follows: The Richter scale
The Richter scale is a scale designed by A. Richter to measure the strength or intensity of the shock waves produced by an earthquake. The scale is measured in steps from one upward. Each successive unit is ten times more powerful than the one before. Therefore an earthquake that measures 7.0 on the Richter scale is 1000 times more powerful than an earthquake measuring 4.0. Little damage is done by an earthquake below 4.0; an earthquake of 7.0, however, would cause widespread
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Earthquakes are most common?
Most earthquakes occur along the boundaries between tectonic plates due to the motion of part of one plate being blocked by another until the pressure or stress becomes too great to be restricted any longer and the previously blocked portion lurches forward. Tectonic plate boundaries are not the only places where earthquakes occur. They can happen in the middle of a tectonic plate. A good example is the New Madrid Earthquakes of 1811-1812 in what is now Missouri, USA.
Why does snow fall only in certain places?
Some places have cold air and some places have hot air.
Cause of deepest earthquakes?
subduction boundary. There are only few places around the world where ultra deep earthquakes happen The subduction boundary partially would answer this question but one of these events happened in SPAIN and there is not subduction zone there DEEPEST earthquakes now, can be divide in two parts, some happens below 300 kms but the deepest ones are below 500 km supposed to be the asthenosphere and supposed to be plastic... ( no brittle)
Do earthquakes happen in same or different places?
Yes volcanoes generally erupt and form on the Borders between tectonic plates under the earths surface, as the route between the earths core and the surface is weaker on these lines. Same with earthquakes, this is when the tectonic plates move or shift against one another
Can earthquakes travel through liquids and solids?
Earthquakes can only happen in solids. Earthquake waves are a different matter:p-waves can travel through both solids and liquidss-waves can only travel through solidssurface waves (e,g, Rayleigh waves, Love waves) can only travel on the surface of solidsetc.
What causes earthquakes and volcanic eruptions happen in certain places and not others?
i only want an answer >:/
What causes earthquakes and volcanic eruptions to happen in certain places and not others?
i only want an answer >:/
Do Earthquakes and volcanoes appear all over the Earth's surface or only in certain places?
Volcanoes are just mostly in certain places and are not dotted around anywhere.
Why are earthquakes only in japan?
Earthquakes are not only in Japan - they happen all over the world. In the last two years there have been notable earthquakes in Japan, China, New Zealand and many other places around the world.
Are earthquakes happening more often?
It depends what area you are in for major earthquakes, but in most places in the world, very weak earthquakes happen nearly everyday. They can only be noticed with special instruments.
Why don't earthquakes and volcanoes happen in some places?
Volcanoes and earthquakes happen when there are tectonic plates below them. The tectonic plates gradually move and might slip after a while. That is when you get an earthquake. A volcano happens when the tectonic plates rub and they get pushed up or down. Malten rock then finds its way through gaps and creates a volcano.
Do earthquakes only happen in flat surfaces?
No earthquakes do not only happen in flat surfaces. Earthquakes happen where ever two faults colide and the vibrations come through and cause an earthquake... (Hope this helps... this is all that i know...)
Does everyone feel an earthquake?
Not everyone, no. Earthquakes happen in certain areas and only those areas will feel it. Of course it depends on how strong the earthquake is.
Where do earthquakes not happen?
Small earthquakes can happen almost anywhere on the earth's surface, however major earthquakes mainly only occur at plate boundaries or along very large faults. Earthquakes can also happen around volcanoes especially when they are due to erupt.
Do earthquakes only happen where plates converge?
no, earthquakes mainly happen when two plates crash each other or one plates goes under the other.
How are earthquakes predicted in California?
Earthquakes are very hard to predict a long time before they happen, they can only br predicted a few minutes before they are going to happen
Where volcanoes and earthquakes occur?
Anywhere where the earths plates meet. Earthquakes occur only were there is an epicenter. Were ever the epicenter is the earthquake will happen.
