Reviewer in Science
PLATE TECTONIC * There are two types of lithospheric plates: * Continental Lithosphere * Oceanic Lithosphere * The solid ground where you stand upon is called the continental crust, lighter them is oceanic crust * This type of crust has several deposits that vary in age forming the foundation of earth’s crust * Basement rock- the oldest foundation which is estimated to be four billion years age. It is mixture of granite and volcanic rocks * After the basement rock are PLATFORMS, younger layer of continental crust, made of sendimentary rocks. When platforms are connected with basement rocks, they are called Cratons * Cratons often survive the cycles of merging and rifting of continents * At the edges of cratons are the Continental Margins * When continental margins are moved by tectonic plates, natural landforms such as mountain ranges * Oceanic Crust- made of heavier basalt and gabbro rocks, younger than continental crust, older for this type is around 200 million years * In terms of thickness, oceanic crust measure only around 7km thick while continental crusts range from 10km to 70km thick * Location: Men will experience a more uniform condition due to the lack of significant typography and our landscape would be older
VOLCANIC
* These plates drift slowly over the mantle below, which is lubricated by a soft layer called ASTHESNOSPHERE * Volcano is a mountain that opens downward to a reservoir of molten rock called Magma, below the surface of the earth * They differ from most mountains because they have vents where molten rock escapes to earth’s surface
HOTSPOT and MANTLE PLUMES * Hotspots and mantle plumes where first observed in the 1960s * John Tuzo Wilson- Canadian Geophysicist and one of the founders of the theory of plate tectonics * Mantle fumes- areas or columns where heat or rocks in the mantle are rising toward earth’s surface * They are located underneath continental or oceanic crust or along plate boundaries * Hotspot are locations on earth’s surface that has experienced active volcanic activities * They are thought to be caused by the convection of hot mantle at the mantle plumes * Volcanism refers to the processes and phenomena associated with the surficial discharge * Convection occurs when matter, such as magma circulates between the earth. It caused by the change in temperature, destiny and pull of gravity. * When magma is heated, it expands and becomes less dense
EARTHQUAKES
* It’s a natural phenomena that is characterized by a sudden, violent shifting of massive plates * This movements of plates releases stress that generates along geologic faults
ANATOMY OF THE EARTHQUAKE