# Earthquakes

### Description

by: Nicole li
Mind Map by Nicole Li, updated more than 1 year ago
 Created by Nicole Li over 6 years ago
10
0

## Resource summary

Earthquakes
1. Section 1: Forces in Earth's Crust
1. Types of Stress
1. Tension

Annotations:

• Tension stretches or pulls on the crust. As an result the rock in the middle becomes thinner.
1. Compression

Annotations:

• Compression squeezes or pushes rocks together until they fold or break.
1. Shearing

Annotations:

• Shearing is stress that pushes rock in two opposite directions.
2. Kinds of Faults
1. Normal Faults

Annotations:

• A normal fault is cause by tension. Its structure includes a footwall and a hanging wall.
1. Reverse Faults

Annotations:

• Reverse faults are caused by compression. Its structure is the same as a normal fault except the reverse fault's blocks move in opposite directions.
1. Strike-Slip Faults

Annotations:

• Strike-slip faults are caused by a type of stress called shearing.
2. Changing Earth's Surface
1. Folding Earth's Crust

Annotations:

• Compression causes Earth's crust to either fold upward, an anticline, or fold downward, a syncline.
1. Stretching Earth's Crust

Annotations:

• The type of stress that causes this is called tension.
1. Uplifting Earth's Crust

Annotations:

• The forces that uplift mountains can also uplift plateaus, which are elevated high, flat, and large land.
2. Section 2: Earthquakes and Seismic Waves
1. Types of Seismic Waves
1. P Waves

Annotations:

• P waves are a type of seismic wave that compress and expand land and can travel through both liquids and solids.
1. S Waves

Annotations:

• S waves are seismic waves that vibrate, and can travel through only solids.
1. Surface Waves

Annotations:

• Sometimes, when P waves or S waves reach the surface, the waves become surface waves.
2. Measuring Earthquakes
1. The Mercalli Scale

Annotations:

• The Mercalli scale measures earthquakes based on their intensity on a scale from 1, the least intensity, and 12, the most.
1. The Richter Scale

Annotations:

• The Richter scale rates earthquakes by giving them a magnitude number based on the size of seismic waves.
1. The Moment Magnitude Scale

Annotations:

• The moment magnitude scale measures how much energy is released during an earthquake.
1. Comparing Earthquakes

Annotations:

• Geologists compare earthquakes using the earthquake's magnitude. An earthquake's magnitude tells how much energy was released during an earthquake.
2. Locating the Epicenter

Annotations:

• Geologists find the earthquakes epicenter by measuring the difference between the arrival of the P waves and S  waves. The greater the time interval between the two waves, the further away the epicenter.
3. Section 3: Monitoring Earthquakes
1. The Seismograph
1. Measuring Seismic Waves

Annotations:

• You measure seismic waves with a seismograph. The pen on the seismograph is heavy so it resists the vibration of an earthquake. The rest of the seismograph vibrates along with the ground when the seismic waves reach it.

Annotations:

• The jagged lines that a seismograph makes is called seismogram. The higher the lines are, the closer or stronger the earthquake is.
2. Instruments That Monitor Faults
1. Tiltmeters

Annotations:

• Tiltmeters measures vertical fault movement by using a carpenter's level.
1. Creep Meters

Annotations:

• A creep meter measure horizontal fault movement using a wire and a weight.
1. Laser-Ranging Devices

Annotations:

• A laser-ranging device uses a laser to detect horizontal fault movement by timing how fast the laser beam takes to travel to a reflector and back.
1. GPS Satellites

Annotations:

• Ground-based receivers use the GPS satellite system to identify changes in land along faults.
2. Using Seismographic Data
1. Mapping Changes Along Faults

Annotations:

• Scientists use seismic waves to detect a hidden fault.
1. Monitoring Changes Along Faults

Annotations:

• Faults that lock together will build up a lot of stress.
1. Trying to Predict Earthquakes

Annotations:

• It is hard for geologists to predict earthquakes because many unexpected things may happen such as an earthquake that stored up a lot of energy but not even happening.
2. Section 4: Earthquake Safety
1. Earthquake Risk
1. Plate Boundaries and Faults

Annotations:

• Two plates meet at a fault. For example, the Pacific plate and the North American plate meets along the San Andreas fault.
1. Mapping Earthquake Intensity

Annotations:

• Geologists use modified Mercalli scale data to map the intensity of an Earthquake.
1. Historic Earthquakes

Annotations:

• Geologists study data from past earthquakes to estimate the probability of future earthquakes.
2. How Earthquakes Cause Damage
1. Shaking

Annotations:

• Shaking can cause a lot of damage including landslides and avalanches. The most violent jolts make take place kilometers away from the epicenter.
1. Liquifaction

Annotations:

• Liquefaction turns loose and soft soil into liquid mud, causing buildings to sink or pull apart.
1. Aftershocks

Annotations:

• An aftershock is a earthquake that may happen hours, days, or even months after the big, major earthquake before.
1. Tsunamis

Annotations:

• When an earthquake jolts the ocean floor, the ocean floor rises slightly, causing water to flow out of its way. The water may become a large wave called a tsunami.
2. Steps to Earthquake Safety

Annotations:

• Please take safety steps when an earthquake strikes. When the earthquake happens, drop, cover, and hold when you are inside.
1. Designing Safer Buildings
1. Protecting Structures

Annotations:

• A base-isolated building is designed to reduce the amount of energy that reaches the building during an earthquake.
1. Making Utilities Safer

Annotations:

• Technology can prevent earthquakes from causing fires and flooding.

### Similar

Biology Revision - Y10 Mock
Biology- Genes and Variation
GCSE Combined Science
Using GoConqr to teach science
Using GoConqr to study science
Acids and Bases
AQA Physics P1 Quiz
Physics Revision
The Circulatory System
Acids and Bases
Elements, Compounds and Mixtures