Earthquake, Volcano, Landslide, and Severe Weather Lecture Notes

This set of flashcards covers key concepts related to earthquakes, volcanoes, landslides, and severe weather, including definitions, types, mitigation techniques, and historical significance.

What is the hypocenter of an earthquake?

The exact point underground where the rock first breaks and the earthquake starts.

What is the epicenter of an earthquake?

The spot directly above the focus on Earth’s surface.

What type of fault occurs at divergent boundaries?

Normal Fault, where rocks pull apart and one block drops down.

What are P-waves?

Fastest seismic waves that compress and stretch the ground, arriving first at seismic stations.

What are S-waves?

Slower seismic waves that move the ground up/down or side-to-side and cannot travel through liquids.

What do surface waves do?

Move along the surface and are the slowest waves, causing the most damage.

What is base isolation in earthquake mitigation?

A technique where buildings sit on flexible pads that absorb shaking.

Which mitigation technique involves strengthening walls to resist movement?

Shear walls.

What is the main action to take during an earthquake?

Drop, Cover, and Hold On.

What hazard ranking includes surface waves and building collapse as the most dangerous?

Earthquake hazards

What factors can increase earthquake risk due to human activities?

Building on soft sediments and poor construction practices.

What is the magma chamber in a volcano?

A big underground pool of molten rock.

Which type of volcano is associated with convergent boundaries?

Explosive stratovolcanoes.

What are warning signs of volcanic activity?

Increased gas emissions, small earthquakes, and ground swelling.

What is a lahar?

A type of volcanic mudflow that can be extremely dangerous.

What are the types of landslides?

Rockfalls, debris flows, slumps, avalanches, and mudflows.

What causes debris flows?

A mix of mud, water, and rocks rushing downhill, which is very deadly.

What are some actions to mitigate landslide risk?

Regrading slopes, building retaining walls, and ensuring good drainage.

What spheres interact during natural hazard events?

Lithosphere, atmosphere, hydrosphere, and biosphere.

What historical storm significantly improved weather forecasting?

Armistice Day Blizzard.

What conditions create heavy snow or ice?

Strong rising motion, moist air, and the correct temperature profile.

What is the main hazard during a hurricane?

Storm surge.

What are ingredients needed for hurricane formation?

Warm water, low wind shear, moist air, and a preexisting disturbance.

What distinguishes a tropical cyclone as a hurricane?

Sustained winds of 39 mph or greater.

What is the purpose of Doppler radar in tornado tracking?

To detect rotation in storm systems.

What is the proper response during a tornado warning?

Go to a basement or lowest interior room, avoiding windows.

What improved tornado death rates since 1950?

Doppler radar, better warnings, faster communication, and public education.

What was a significant lesson from Hurricane Katrina?

The need for stronger levees and better communication for evacuations.