Distribution of Hydro-Meteorological Hazards
Earthquakes: There are several different types of faults which means that the locations of different risks vary and the types of quake also differs.
Destructive: This is the boundary in which oceanic crust is being subducted beneath a continental plate, or where two oceanic crusts collide. These can either be shallow, intermediate or deep. The force of compression as the plates meet causes stresses in the crust, so when released it causes violent shaking. That point is the focus and the nearest point above, on the ground is the epicenter. However when two continental plates collide, fold mountains are formed; this is when shallow, highly damaging quakes happen. An example of this is India and Iran. Constructive: These quakes are usually submarine so pose little iminent threat to human life. This is when oceanic plate move away from eachother, allowing for magma to rise and create new land. These are shallow and low magnitude. Conservative: Quakes happen here when two late either grind past eachother in opposite directions or go in the same directions at different speeds. As the plate edges are not smooth, the movement is often rough and tension builts up, so when they release they can produce very high magnitudes and can be fairly frequent. Lateral crust movement means that they can be quite shallow and are sometimes at very high risk to humans, depending on the location. For example, The San Andreas fault line in California. Because California is in an MEDC and is in a very built-up area, when a quake happens it can put a lot of people at risk and is at a large cost. Other Quakes: 1. A small amount of earthqaukes occur in the middle of a plate, due to ancient fault lines that were once there. Such as the UK, however, these are usually of low magnitude and little risk to humans. 2. Very occasionally, human factors, such as the building of a damn could cause an earthquake. Another factor to take into account is the humans in the location that an earthquake happens in. If an earthquake happened in an LEDC, then they would not be able to have the preventions in place that can help to reduce the impacts of a quake on humans. They would'nt have the funds to help with the aftermath and aiding those in need of help. However, MEDC's are more likely to be able to survive bad quake as they will have the money to make their infrastructure better, have evacutaion policies, etc. that is not possible for LEDCs. Also, population density is also important regardless of whether you are an LEDC or MEDC. For example, California is an MEDC but because the San Andreas fault is in a built-up area, when a quake happens, it can be difficult to recover (1989 San Francisco). |
LO: to fain a greater understanding of the distribution of geophysical hazards,
A- Evaluating B- Explaining C- Describing hjhkj
To the side is a link to a video plotting all of the earthquakes, big and small that occured during 2011. It is interesting to see how they are distributed across the world and how some areas are more prone to these then others.
Different natural disasters occur in different places around the world due to environmental differences. For example, the temperature of a location may mean that it has more or less hurricanes in warmer places than colder places, because they may have warmer air and be more humid. Not only may the weather be a factor, but so is the geographical location. By this I mean, fault lines and plate boundaries will effect whether or not a location is prone to earthquakes or even volcanic eruptions. For example, California is at a very large risk of being affected by earthquakes because they are nestled between some very active fault lines, such as the San Andreas Fault. But the UK not at as bigger risk because they are in the middle of a plate. This does not necessarily mean that they are safe from all quakes, as there can occasionally be earthquakes in the middle of faults, but these are usually low risk and not too harmful. Interesting and fun facts about volcanoes!
|