Due to high temperatures in the mantle of around 3000 degrees centigrade, this oceanic crusts melts and then rises due to the convection currents in the aesthenosphere . As it joins with trapped seawater and sediment, it melts the overlying continental crust, and the magma plumes rise to the surface. They contain more silica so are more viscous, which plugs up the volcano, meaning pressure build up. This is why these volcanoes are so explosive. Another type of plate boundary are constructive, which is the margin between two diverging plates where new magma
'The extent to which volcanic processes represent hazards depends on where and when they occur.' Discuss this statement. Volcanic processes become a hazard when they impact upon the human and built environments, killing and injuring people, burying and collapsing buildings, destroying infrastructure and bringing agricultural activities to a halt. Volcanic hazards are influenced by several factors including location, time and frequency of eruptions, and the materials ejected. It is the viscosity of magma that largely determines the nature and power of an eruption and the resultant severity of the hazard.
There is a convergent boundary on the west side of the United States. At a convergent boundary, two plates collide, and the denser plate is subducted. Volcanoes and earthquakes are common as a result of pressure and friction. There is also a transform boundary forming the San Andreas Fault which is between an oceanic plate subducting under a continental plate. 3.
At destructive plate margins, the oceanic plate goes under the continental plate due to it’s more dense, which is a process known as subduction. The oceanic plate moves down into the mantle entre the benioff zone where it’s melted and destroyed because a pool of magma formed. The magma then rises through the cracks in the crust called vents and it erupts on the surface forming a volcano. There are also different types of volcano for examples composite volcanoes, shield volcanoes and dome volcanoes. For constructive plate margins, the magma rises up into the gap that created by the plate move apart to form a volcano.
Gore also asserts that global warming is caused by over population. Toxins and chemicals in the atmosphere impact each individual in the world. Because of the effects of global warming, the strength of hurricanes can change easily and cause an enormous amount of
This would be terrible for the people and creatures that rely on this mighty river to live. Dams, diversions and evaporation losses from reservoirs also contribute to the lessening of water available from the river, causing ecological consequences to wildlife living in and along the river. The Colorado River used to carry up to 85 to 100 million tons of silt or sediment to the Gulf of California where it deposited into the sea. The sediment helped things along the river path grow and flourish. Over the years, the silt has been collecting in Lake Mead, the nation’s largest reservoir, and it is predicted that over the next few hundred years this lake will fill up with silt.
The raise of the temperature has been affecting humans and animals. Glaciers started to melt really fast which is affecting the animals that live in the north/south pole. Hydrofracking will make us alot of money and would let us to make our own natural gas and wouldnt have to get it from somewhere else but we are harming our environment we havent going to last here if we keep messing with
But if my opponents did any research, they would realize that there is plenty of evidence to show that global warming is a real threat to this earth. In his essay “Now Or Never”, Bill McKibben writes: Consider hydrology, for instance. Warm air holds more water vapor the cold air, so there is an increase in evaporation in dry areas, and hence more drought—something that has been documented on every continent. Once that water is in the atmosphere, it’s going to come down someone—and indeed we have seen the most dramatic flooding ever recorded in recent years. In 1998, 300 million humans, one in twenty of us, had to leave their homes for a week, and month, a year, forever because of rising waters.
Carbon dioxide is a heat trapping greenhouse gas. It gets “released through human activities such as deforestation and burning fossil fuels, as well as natural processes such as respiration and volcanic eruptions” (Global Climate Change: Key Indicators, 2014). An increase in carbon dioxide means more heat is trapped thereby raising the Earth’s temperature. Global surface temperature needs to also be monitored. Not just one area but globally!
General economic standing: 4. Has the tectonic setting (which also influences the geography or landforms) influenced population concentrations? 5. General description of the earthquake or volcano in terms of tectonic setting, frequency or historic activity, why event occurred (volcano and subduction zone generally produce viscous lava and violent eruptions) or (earthquake and subduction zone are capable of producing large volume of crustal movement =large magnitude earthquakes and tsunami). a. Volcano: include the type of lava, where magma is derived, and why this setting produces hazards b. Earthquake: magnitude and amount of displacement or offset 6.