Friday, February 10, 2017

San Andreas: Natural Disasters - Earthquakes

My guilty pleasure is natural disaster movies. It is a shame there have not been good ones around lately. This one is an exception, though.

Interview a partner:

  • ·         Have you ever experienced an earthquake or a natural disaster?
  • ·         When was the last earthquake that you remember?
  • ·         Has your house been damaged by an earthquake or any other natural disaster?
  • ·         What happens during an earthquake?
  • ·         What areas of the world have many earthquakes?*
  • ·         Is it possible to know in advance that an earthquake is coming? **
  • ·         Where is the best place to go during an earthquake? ***
  • ·         Is an earthquake always followed by a tsunami? ****
  • ·         What causes aftershocks? *****

Answer key:

* Earthquake danger zone map:

An earthquake zone is a region in which seismic activity is more frequent. It is impossible to predict earthquakes with precision and most high-activity earthquake danger zones are situated along the fault zones. Fault zones that are prone to seismic activity are regions of the Earth's crust are those areas where tectonic plates meet. Therefore, fault zones are also located around volcanoes. Some important parts of the world which lie in fault zones and where earthquakes are regularity are:

California through which the San Andreas passes and also the Hayward fault zone located in the San Francisco Bay, where the North American and Caribbean tectonic plates meet. 

Padang, the capital of West Sumatra province of Indonesia, is located on some of the world’s most dangerous fault zones.

Islamabad, capital of Pakistan, is located on major fault lines which lie in the meeting of the Iranian and Arabian micro-plates making it a highly dangerous region for seismic activity.

The country of Iran is located in the Alpine-Himalayan belt which is an active seismic zone.

Japan which is located on the convergence of many oceanic and continental plates has many densely populated cities of Tokyo and Yokohama.

Mexico is located on the convergence of three of the earth’s tectonic plates.

Similarly, Vancouver Portland and Seattle lie in the dangerous Cascadia Subduction Zone.

The Xianshuihe, Min Jiang and Kunlun fault lines also passes through China.

The Eurasian and African tectonic plate passes through the south of Italy making the country vulnerable to earthquakes.

** Scientists have tried lots of different ways of predicting earthquakes, but none have been successful. They have a pretty good idea of where an earthquake is most likely to hit, but they still can't tell exactly when it will happen.
However, the probability of a future earthquake can be calculated, based on scientific data. Scientists at the US Geological Society (USGS) estimate that the probability of a major earthquake occurring in the San Francisco Bay area over the next 30 years is 67%.

*** Indoors: Drop, cover, and hold on. Drop to the floor, take cover under a sturdy desk or table, and hold on to it firmly. Be prepared to move with it until the shaking stops. If you are not near a desk or table, drop to the floor against the interior wall and protect your head and neck with your arms. Avoid exterior walls, windows, hanging objects, mirrors, tall furniture, large appliances, and kitchen cabinets with heavy objects or glass. Do not go outside!
Outdoors: Move to a clear area if you can safely do so; avoid power lines, trees, signs, buildings, vehicles, and other hazards.
Driving: Pull over to the side of the road, stop, and set the parking brake. Avoid overpasses, bridges, power lines, signs and other hazards. Stay inside the vehicle until the shaking is over. If a power line falls on the car, stay inside until a trained person removes the wire.

**** Not always. It depends on the magnitude, the directions of the frictions, distance from the coast. How deep the epicenter was and many other variables.

***** An aftershock results from the sudden change in stress occurring within and between rocks and the previous release of stress brought on by the principal earthquake. Aftershocks occur in rocks located near the epicenter or along the fault that harbored the principal quake.

Watch the movie segment and say what you would  in that  situation. 
Do you ever think about how vulnerable a city or country you are visiting is to an earthquake or a natural disaster (San Francisco, Seattle, Italy, Chile, Japan, among others)?