Costa Rica

Geography Inquiry

January 8, 2016 - Conclusion

Earthquakes that hit populated areas are more likely to do more damage. San Jose is in a very earthquake prone location. We cannot move the city, so we would need to improve the infrastructure on existing structures. To do that we could wrap steel frames around important buildings to make them less likely to collapse in the event of an earthquake. With the steel frames, buildings could stay up longer and would cost less money because they would not have to rebuilt as often. Also, we can save more lives. New communities can be built outside earthquake prone areas, so it will be less likely for a large quake to strike the area.

January 8, 2016 - How can we improve infrastructure to prevent destruction from earthquakes?

  • Build infrastructure away from earthquake prone areas
- Reduce economical damage

- Lower death rate

  • Authorities can implement guidelines on locations and set limits on building heights
  • Infrastructure specially designed with newer technology to withstand stronger tremors
  • Wrap steel frames around pillars of buildings and bridges

January 8, 2016 - How do Costa Ricans adapt after an earthquake?

  • Beware of aftershocks

- Smaller than main earthquake

- May cause additional damage

  • Other effects: fires, chemical spills, landslides, etc.

January 8, 2016 - What makes earthquakes destructive?

Location: An earthquake that hits a populated area is more likely to do damage than one that hits an unpopulated area or in the middle of the ocean.

Magnitude: The stronger the earthquake, the more destructive it will be.

Depth: Earthquakes can happen anywhere from the surface to 700 kilometres in depth. The deeper the earthquake, the less damage it does because the energy dissipates before reaching the surface.

Distance from the epicenter: The epicenter is the point where the earthquake happens. The closer to the epicenter, the stronger the earthquake.

Local geologic conditions: The ground at the surface of the earthquake can greatly affect the amount of damage done. Loose, sandy soil are more likely to cause buildings to collapse.

Secondary Effects: Earthquakes can trigger landslides, fires, floods and tsunamis. They can do more damage than the earthquake itself, if triggered.

Architecture: Better architecture is more likely to survive a quake. Poor construction and weak cement can worsen damage.

2012 Costa Rica Earthquake

Wednesday, Sep. 5th 2012 at 8:45am

Nicoya Peninsula, 10.16 N; 85.39 W

January 7, 2016 - Contacting an Expert

I contacted Wayne D. Pennington who is a Professor of Geophysical Engineering, Geological and Mining Engineering and Sciences at Michigan Tech. He answered two of my questions:

At what frequency do earthquakes have to happen at for buildings to be built to withstand earthquakes?

What is the safest type of structure?

December 8, 2015 - 2012 Costa Rica Earthquake

The 2012 Costa Rica Earthquake was magnitude 7.6 and struck on September 5, 2012. A tsunami warning was issued, but cancelled, but the quake caused little damage. One death was confirmed. Some houses and one bridge collapsed, and landslides blocked highways, but otherwise there was no major damage. The quake was somewhat deep - 41 kilometres below the surface. Earthquakes that occur deeper underground cause less damage, but are more widely felt. The epicentre was 60 kilometres from the town of Liberia and 140 kilometres west of the capital, San Jose. The earthquake was followed by three aftershocks of magnitudes 4.6, 4.5 and 4.4. The tsunami warning caused 5 000 people, about 80% of the population of the town of Samara, to evacuate. This area is seismically active, where the Cocos tectonic plate dives under the Caribbean plate. This was the largest earthquake since the 1991 Limon Earthquake which killed 47 people.

December 2, 2015 - My Questions So Far

Knowledge questions:

What factors contribute to the destructiveness of an earthquake?

Open-ended questions:

How do Costa Rican residents adapt to their new lifestyles after the event of an earthquake?

Main Question:

How can we build on the infrastructure of the country to prevent more damage caused by earthquakes?