Intrusive igneous rocks, also known as plutonic rocks, are formed inside earth's crust. Molten rock rises and fills openings or melts overlaying rocks. This eventually hardens creating an intrusive igneous rock. An extrusive igneous rock, or volcanic rock, is created by magma rising the earth's surface. Magma is known as lava when it reaches the surface.
How to predict an volcanic eruption Ground Deformation Ground deformation is the change in shape that happens before during or after a volcanic eruption. This happens because the sides of the volcano change shape because the magma in many ways to measure the change of shape of the volcano, like leveling, triangulation and more recently using continuous Global Positioning System (CGPS). It is also possible to use lakes as large tilt meters. Tilt meters measure the tiny degrees of tilt or slope on land. This is one of the oldest methods of knowing when ground deformation was caused because of rising lava.
The reason for the movement is convection currents originating in the core caused by radioactive decay. Knowing the theory of plate tectonics is a useful tool in understanding the distribution of earthquakes and volcanoes as they correlate very closely. If we map out the location of major earth quakes, location of active volcanoes and a map of general plat tectonic, the 3 would overlap. This gives us a general idea of locations and correlations. Each boundary between 2 plates have the capability of being a different type of boundary.
Plate Tectonic Theory What is Plate Tectonics? Plate tectonics is the main force that shapes our planet’s surface over a long period of time the study of how the Earth's crust is shaped by geological forces. It relies on the understanding that the crust is divided into large pieces, or plates, that sit on the molten interior of the planet. Currents within the interior cause the plates to move, which causes many different geological events, including earthquakes and the forming of mountains and volcanoes. Understanding how plates move and interact is the main purpose of plate tectonics.
The force of one plate being dragged under another causes intense friction and the pressure increases. Eventually, there is so much pressure that the plates suddenly jolt, causing an earthquake. Where an oceanic plate meets a continental plate, sediments are thrust upwards. Due to the friction caused by the plates scraping against each other, the temperature in the mantle increases. Magma rises forming a long chain of volcanic fold mountains for example the Andes.
Earthquakes are caused by the rift and abrupt movement of two rocks that suddenly slip past one another. Earthquakes occur along faults which are fractures in the lithosphere where sections of rock move past one another. There are three important parts to an earthquake: the focus, the epicenter, and seismic waves. The focus is the point on the fault where the separation occurs and from where the seismic waves are formed. The epicenter is located directly above the focus on the earth’s surface.
The cycle returns carbon to the atmosphere through volcanoes. Earth’s land and ocean surfaces sit on several moving crustal plates. When the plates collide, one sinks under the other, and the rocks it carries melts under the extreme heat and pressure. The heated rock recombines into silicate materials, releasing carbon dioxide. When volcanoes erupt, they vent the gas to the atmosphere and cover the land with fresh silicate rock to start the cycle
Alfred could not explain how the huge masses of land could have moved so far. The major means for the lithospheric plates to float on the asthenosphere comes from the process of convection in the mantle of the Earth. Heat from the outer core rises in the mantle and “melts” the upper part, which is called the asthenosphere. The plates of the lithosphere move in three main ways. There are divergent boundaries where the plates are moving away from each other and new land is formed as magma is released from inside the mantle.
J. Subbiondo © 2004The CrustThe outer layer of the Earth is called the crust. It is made up of rock that floated to the surface when the Earth was formed. It is not a continuous layer, but is made up of large masses called tectonic plates.These plates drift slowly across the Earth's surface (tectonic means moving).The movement of these plates creates mountains and valleys.At weak points in the crust, it causes volcanic eruptions. And when plates bump into each other, earthquakes occur -- emitting shock waves or vibrations called seismic waves. The crust is the Earth's coldest layer.
Diamond-bearing rock can be transported from the lithosphere to the Earth's surface through volcanic eruptions, which form very deep within the earth. This takes place when small surface volcanic craters extend downward in formations known as volcanic pipes