TEKS:
7.14A: describe and predict the impact of different catastrophic events on the Earth
Scope and Sequence:
Aldine: 7th grade - 5th 6 weeks Cy-Fair: 7th grade - 2nd 6 weeks
Big Ideas:
A catastrophic event is a rare event where people are killed, injured or displaced, results in property damage and results in geologic or geomorphic change.
Three big ideas:
1. Size vs frequency (large events are rare) - recurrence intervals are not always predictable
2. Events can be categorized into 4 basic types based on causes:
3. Risk assessment = probability of occurence x damage
1) Size vs. Frequency: All natural processes occur on different scales. For example, small earthquakes occur every day throughout the world, but most are so small that they are detected only by seismic monitoring equipment and cannot even be felt by people, even at the epicenter. On the other hand, large earthquakes that are catstrophic in scale occur very rarely, which is why we hear about them on the news. The larger the earthquake, the less likely that it will occur at a given time.
This is true of the other natural events that can become catastrophic. We see plenty of thunderstorms, but hurricanes are rare. Small emissions of gases and even lava come out of the mantle almost daily, but large volcanic eruptions make the news. Winter in the northern U.S. means plenty of small snowfalls, but blizzards come rarely. Space dust falls through our atmosphere all of the time, but we rarely see meteors that are large enough to even make it to the Earth's surface before disintegrating. In risk assessment, then, we attempt to predict the probability of occurence of a catastrophic event. Most often, we use monitoring devices and historical data to try to understand whether the events are cyclic and/or predictable.
2) The four basic types of events often happen with different frequencies. Weather-related catastrophic events are usually more predictable than other types, because they tend to be seasonal, and there is some historical record of occurrences that we can use to predict the future behavior of the weather. With the link to plate tectonics, we can easily predict where volcanoes, earthquakes, and other tectonic events will occur, but it is much more difficult to predict when they will happen. Space-related events are extremely rare, and, unfortunately, very unpredictable. Events caused by human activity happen fairly often, but exactly when and where they will occur is difficult to predict.
3) Risk assessment is important because these catastrophic events impact people's lives and homes, as well as the ecosystems. Besides the timing of these events, the locations are also very important in determining the risk. A large earthquake high in the Himalayan mountains (such as the one on June 24th), where there are no permanent settlements will do less damage and affect almost nobody, compared to the same size earthquake in Taiwan (such as the one on June 28th), where many people live and many buildings, roads, and other infrastructure would be damaged. The damage part of the risk assessment equation includes population density, size and ages of cities, as well as building codes in the local area.
Case Study:
Hurricane Ike made landfall on September 13th, east of Galveston, Texas, as a Category 2 hurricane at 2:10 a.m. CDT. This hurricane was the strongest storm in the 2008 season. The damage to the upper Texas coast was catastrophic leveling cities, homes, and lives. Hurricane Ike not only effected Texas but left distruction all along it path from Turks and Caicos, Bahamas, Haiti, Dominican Republic, Cuba, Florida Keys, Mississippi, Louisiana, Texas, Mississippi Valley, Ohio Valley, Great Lakes region, even into eastern Canada and as far away as Iceland.
Locally residents were without resources including water and power for upwards of six weeks. Here are some incredible pictures, pictures from space, and videos of hurricane Ike.
Good Research questions:
Can we use historical data to show a pattern in earthquakes occurence, locally, world wide? Can we use these data to
predict when the next large earthquake will occur?
What is the probability of a natural disaster occurring near your home? What is the most likely type to occur? What is the
least likely type to occur in your area?
What is the population density in your area? What are the building codes in your area that address the damage of
catastrophic events?
What can we do to minimize the impact of the catastrophic events that are likely to occur near your home?
Not so good research questions:
Do earthquakes occur at certain times of the day? This is a yes or no question, which is not a good scientific question.
It can be reworded as above to become a better question to investigate.
Are earthquakes seasonal? Again this is a yes or no question, and could be expanded to be a better question.
Do we have earthquakes in Harris county? Again this question is too narrow.
Simulated Research Activites:
Stormpulse.com - Watch the development and changes of Hurricane Ike (and compre with other storms)
Earthquake data (excel spreadsheet of 1 week's earthquake activity) or get your own by following these directions
Earthquake data (list of historic earthquakes worldwide - sorted by magnitude)
Maps and status of Volcanoes in the U.S. (also links with worldwide maps and info)
Short Videos You Might Find Useful:
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