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.

Drought...it effects us more than we think.

In my geography lab, we covered some more very pertinent information once again. This time, we talked about drought (more specifically, drought in the United States). First, we talked about the Palmer Drought Severity Index (PDSI), which is a way of determining “dryness” of an area by measuring the temperature and amount of rainfall. We found that the worst areas of the U.S. affected by drought are the Midwest, as well as the southeast. We did all fo this with Google Earth. Next, utilizing the ArcMap program, we found once again the Midwest of the U.S. was most affected by drought (see map below). This is noteworthy because most of our agriculture is grown in the Midwest and a severe amount of drought will directly affect the amount of crop yield. We do not feel the effects of this too much simply because we are a rich country (or a "More Developed Country"/"MDC"). Because our average crop yields are almost always more than we need to survive, when we experience a drought, and because of the excess in crop yields, even if there is a shortage of crops we still have more than enough to feed the population. However, as we have started to see, this will most likely affect the prices of not only crops, but also foods from livestock. Because we need to feed livestock with our crops, if there is a shortage of crops it will not only affect how many crops are available for consumption, but it will affect how much food is available to feed our livestock; this, in turn, affects how much meat is available. The bottom line is: the less food there is, the higher the prices will be because it now costs more for farmers to raise their crops and livestock.

Next, we took a quick look at the "USA Soil Survey" (see map below) which shows where "good" and "bad" soil is located in the U.S. We found, believe it or not, that the majority of the good soil (green colored on the map) lies within the Midwest (the same area I spoke of earlier). On a side note, the green colored soil on the map is known as "Mollisols" which is a soil order that is the richest within the continental United States; it produces, or it should produce, the highest yield of crops and is found mostly in the Midwest.

We then looked at soil orders and found that areas that are normally supposed to be high-yielding in crops are actually not yielding nearly as much. Looking at the map below, the areas that are darker green show low crop yields; the darker green lies directly where the mollisols soil order is.

After looking at all of the information, one can develop an understanding of how crop yields are being affected. By looking at the types of soil that lie within the U.S., as well as the PDSI, we know that over the past 100 years, there has been a continual trend of an increased amount of drought. This increased drought, because of its location (i.e. the Midwest), will decrease the amount of crop yields, which will increase the prices of foods.

Messing around with more GIS

Last lab we got to mess around with some more GIS (Geographic Information System) software again; this time, however, we got to take a closer look into earthquakes (with the system called “arcgis”) and the type of data that is stored from around the world.  First, we took a look at areas in Southeast Asia (Figure 1) and how many earthquakes occurred in that area.  We took note of how dense populations were near areas containing a high frequency earthquakes; that is, many earthquakes occurred along the Earth’s plates and these plates happened to be right near many coastlines.  Because of this this there was a greater chance of a tsunami that could devastate populated areas.  Additionally, we took a look at the Mediterranean area and found that many earthquakes occurred along mountain ranges (also the location of many the Earth’s plates).  The bottom line of this exercise was to take note how governments and private organizations can help prepare to mitigate the damage of natural disasters.  With this data, these organizations can know where the majority of earthquakes occur and possibly save many lives and prevent excessive damage from occurring.

Figure 1.  Location and magnitude of earthquakes in Southeast Asia and Australia.

Figure 2.  Location and magnitude of earthquakes in the Mediterranean.

After this we analyzed the magnitudes of earthquakes across the globe (Figure 3).  We found that the regions with the strongest earthquakes are the southeast Pacific, Indonesia, and Central America.  We also found that the majority of earthquakes occur along the fault lines that I mentioned earlier.  However, these are several earthquakes (even those of a greater magnitude) that occur away from the fault lines, as well.  This is because, even though larger earthquakes are more likely to occur along fault lines, it does not mean no earthquakes (even large ones) will happen away from them.  With this in mind, organizations should still have emergency plans in place if natural disasters (even unexpected ones) occur.

Figure 3.  Magnitudes of earthquakes across the globe. The larger the blue dot, the greater the magnitude.  Red dots signify earthquake with a magnitude greater than 8.0.

One question we were asked in lab was “How does the information in this lab relate to hazard risk assessment?”  The information we covered in lab is critical in developing hazard risk assessments simply because developing these assessments involves a lot of research and one of many steps involves investigating where past hazards have occurred.  In terms of earthquakes, data from arcgis shows that the majority of earthquakes occur along the Earth’s plates.  The data also shows what areas of the Earth at a higher risk (i.e. LDCs are more likely to get hit and take more damage than MDCs).

Overall, this lab was very helpful in learning more of how the experts have adapted in the use of different technology.  It also helped in learning how they can aid in the mitigating the amount of damage caused by natural disasters.  I look forward to using this technology in class more and continuing to learn about it even more.