EARTHQUAKE!!!!

Once again, we got to play around with some pretty cool ArcGis stuff, this time related to earthquakes. Intially, we took a look at fault lines and found that there is a greater chance of earthquakes occurring along fault lines; this is useful for experts as it allows them to better prepare for earthquakes in the future. We then analyzed the amount of ground motion and the amount of shaking during and earthquake. The bottom line of these exercises were to provide us with the knowledge that the more that experts know, the better they can help agencies to prepare for future disasters. For instance, areas that are highly populated and are right along (or right near) a fault line most-definitely need more preparation for earthquakes. If more preparation is done, it not only can save more lives, but it also can save a lot of damage to things such as infrastructure. After analyzing that basic earthquake stuff, we then delved into a section called "earthquake loss and destruction" which focused on, well, what earthquakes do in terms of loss and destruction. First, we analyzed the damage to building caused by an earthquake in Northridge, CA. The maps below show the status of the buildings: the first shows the density of damage (i.e. how much damage was caused to the buildings) from the earthquake and the second shows the "status" of those buildings (i.e. whether use of those buildings were safe, limited, or unsafe).

Next, we took a look at liquefaction, which is where soil loses it's strength (mostly during an earthquake) and gives way, causing damage to infrastructure (e.g. buildings, roadways, etc.). Below is a map showing the liquefaction from the earthquake ranging from moderate to high to very high. It is interesting to note that the amount of liquefaction from the earthquake is closely related to the damage done to buildings.

Lastly, we looked at two other terms: peak ground acceleration (PGA) and peak ground velocity (PGV). We found that there is a higher level of accelerartion at the focal point of the building damage. The maps below show this (the first shows PGA; the second shows PGV).

All in all, the use of ArsMap in this lab gave us a deeper unstanding of how experts can prepare for environmental hazards. ArcGis allows for experts to fully understand the effects of an earthquake. It allows them to view the amount of acceleration as well as the velocity and compare the two to dictate not only where the majority of the damage was during the earthquake, but also it will help for future planning of future earthquakes. It allows them to pass that information along to building contractors and government agencies to better prepare populated areas in the event of an emergency. At the end of the lab we were asked what forms of data would prove to be useful in putting together a GIS analysis? I said that the amount of population density would prove to very helpful in order to predict things such as the amount of warning time an urban area would need; population density would also allow governments in deciding how much money to sanction to a given area in order to prepare for an emergency. Also, the amount of current preparations set up for an earthquake in urban area would prove useful in this regard, as well.