Presentation is loading. Please wait.

Presentation is loading. Please wait.

 Explain how earthquake-hazard level is determined.  Compare methods of earthquake forecasting.  Describe five ways to safeguard buildings against.

Similar presentations


Presentation on theme: " Explain how earthquake-hazard level is determined.  Compare methods of earthquake forecasting.  Describe five ways to safeguard buildings against."— Presentation transcript:

1

2  Explain how earthquake-hazard level is determined.  Compare methods of earthquake forecasting.  Describe five ways to safeguard buildings against earthquakes.  Outline earthquake safety procedures.

3  Seismologists are not able to predict the exact time when and place where an earthquake will occur.  They can, at best, make forecasts based on the frequency with which earthquakes take place.

4  Earthquake hazard is a measurement of how likely an area is to have damaging earthquakes in the future.  An area’s earthquake-hazard level is determined by past and present seismic activity.  The greater the seismic activity, the higher the earthquake-hazard level.

5

6  Forecasting when and where earthquakes will occur and their strength is difficult.  By looking carefully at areas of seismic activity, seismologists have discovered some patterns in earthquakes that allow them to make some general predictions.

7  Earthquakes vary in strength. And you can probably guess that earthquakes don’t occur on a set schedule. But what you may not know is that the strength of earthquakes is related to how often they occur. Table 1 provides more detail about this relationship worldwide.

8  Great 8.0 and higher 1  Major 7.0–7.9 18  Strong 6.0–6.9 120  Moderate 5.0–5.9 800  Light 4.0–4.9 about 6,200  Minor 3.0–3.9 about 49,000  Very minor 2.0–2.9 about 365,000

9  Another method of forecasting an earthquake’s strength, location, and frequency is based on the gap hypothesis.  The gap hypothesis is a hypothesis that states that sections of active faults that have had relatively few earthquakes are likely to be the sites of strong earthquakes in the future.  The areas along a fault where relatively few earthquakes have occurred are called seismic gaps.

10

11

12  Today, older structures in seismically active places, such as California, are being made more earthquake resistant.  The process of making older structures more earthquake resistant is called retrofitting.  A common way to retrofit an older home is to securely fasten it to its foundation.

13  A lot has been learned from building failure during earthquakes.  Armed with this knowledge, architects and engineers use the newest technology to design and construct buildings and bridges to better withstand earthquakes.

14

15  The first thing you should do is safeguard your home against earthquakes.  You can do so by putting heavier objects on lower shelves so that they do not fall during the earthquake. You can also talk to a parent about having your home strengthened.  Next, you should find safe places within each room of your home and outside of your home.  Then, make a plan with others (your family, neighbors, or friends) to meet in a safe place after the earthquake is over. This plan ensures that you will all know who is safe.

16  During the earthquake, waterlines, power lines, and roadways may be damaged.  So, you should store water, nonperishable food, a fire extinguisher, a flashlight with batteries, a portable radio, medicines, and a first-aid kit in a place you can access after the earthquake.


Download ppt " Explain how earthquake-hazard level is determined.  Compare methods of earthquake forecasting.  Describe five ways to safeguard buildings against."

Similar presentations


Ads by Google