The Sierra Nevada Mountains on the Pacific coast of North America and the Andes on the coast of South America were cited. Wegener also suggested that India drifted northward into the Asian continent thus forming the Himalayas. Many other scientist provided evidence toward this theory of a “continental jigsaw”, this evidence included geological matches in the rock type on two different continents coastlines found thousands of miles away e.g. Scotland and Canada and South America and Africa. Fossil evidence was also provided; trilobites of the same species found in Canada and Scotland and also, coal deposits were located in Antarctica.
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.
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.
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.
These are boundaries where the plats move towards each other but 1 plate travels underneath (subduction). The less dense oceanic plate is the plate that subsides under the denser continental plate. The oceanic plate with melt as it falls to the asthenosphere creating a mantle plume where we expect to see a strombolian (cone) volcano. These volcanoes are typically tall cone shaped volcanoes. They are as such because they lava is andesitic/rhyolitic which means the lava contains 55%+ silica content.
Cold Seeps A cold seep (sometimes called a cold vent) is an area of the ocean floor where hydrogen sulfide, methane and other hydrocarbon-rich fluid seepage occurs. Cold seeps are distinct from hydrothermal vents: the former's emissions are of the same temperature as the surrounding seawater, whereas the latter's emissions are super-heated. Cold seeps constitute a biome supporting several endemic species. Cold seeps occur over fissures on the seafloor caused by tectonic activity. Oil and methane "seep" out of those fissures, are diffused by sediment, and emerge over an area several hundred meters wide.
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.
Even though the coastlines didn’t match perfectly (maybe due to erosion/weathering), he later found that the continental shelves matched more closely which matched the theory that those continents were once together. The strongest evidence for continental movement is the study of paleomagnetism. The study of the intensity and orientation of the Earths magnetic field is preserved in the magnetic orientation of certain minerals found in rocks formed throughout geologic time. A study of the ocean floors have demonstrated that the orientation of the earths
The Era is made up of six Geologic periods, the Cambrian, Ordovician, Silurian, Devonian, Carboniferous, and the Permian. Much of the plants and animals that exististed and evolved was due to the climate and location of the continents. At the beginning of the Paleozoic period, the continents were far apart, but by the end they were close together and on the way in forming the supercontinent called Pangaea. The land was moving by Plate Tectonics. Four hundred and thirty million years ago there was glaciation; this caused an ice sheet to cover what is now North Africa.