Exam 3 - Geol 101 - pt 2

What is the definition of the epicenter in relation to an earthquake?

point on the earth’s surface directly above the focus.

What is the focus of an earthquake?

point within the earth where the earthquake originates.

What are P waves and what are their characteristics?

fastest, weakest body waves that can travel through solids, liquids, and gases

What are S waves and what are their characteristics?

second fastest body waves that have an up and down motion, only pass through solids.

What type of seismic wave is the most destructive?

Surface waves, the slowest and wave like motion

What does the Richter scale measure?

The Richter scale measures the amplitude of the largest seismic waves

What is a significant limitation of the Richter scale?

does not perform well in measuring the largest earthquakes.

How much energy increase does each unit of magnitude represent on the Richter scale?

Each unit increase on the Richter scale represents a 32-fold increase in energy.

How does the Moment Magnitude scale differ from the Richter scale?

better for large earthquakes and uses the area and amount of slip to measure the earthquake's energy.

How do you calculate the difference in magnitude between two earthquakes?

Subtract the magnitudes and make the difference the exponent of 32.

What is the modified Mercalli intensity scale used for?

used to measure the intensity of an earthquake through 12 divisions using Roman numerals.

What factors can affect earthquake intensity measurements?

Intensity measurements may not reflect the true size of an earthquake as they do not take many factors into account.

What are some common hazards associated with earthquakes?

Common earthquake hazards include ground shaking, fires, landslides, avalanches, tsunamis, and flooding.

What is a crucial design feature for large buildings to withstand earthquakes?

Big buildings need good support on the bottom to withstand earthquake forces.

Why can 3-4 story buildings be particularly vulnerable during an earthquake?

3-4 story buildings can have resonance that matches the earthquake waves, potentially causing them to collapse.