Terms in this set (28) When a fault is expressed at the surface, it is called a. fault scarp. The name of the site where slippage begins and
What is the name given to the location in which slippage begins and earthquake waves radiate outward from?
The location where slippage begins is called the hypocenter, or focus. Earthquake waves radiate from this spot outward into the surrounding rock. The point on Earth’s surface directly above the hypocenter is called the epicenter (FIGURE 8.2).
What is a surface earthquake?
A surface wave is a seismic seismic wave that is trapped near the surface of the earth.
Which of the following might generate an earthquake?
Earthquakes are usually caused when underground rock suddenly breaks and there is rapid motion along a fault. This sudden release of energy causes the seismic waves that make the ground shake.
Why is moment magnitude preferred over Richter magnitude?
Why is moment magnitude (MW) preferred over Richter magnitude (ML)? Moment magnitude measures the total energy released during an earthquake and can adequately measure the energy of large earthquakes. Which of the following best describes liquefaction? Describe how sand volcanoes form.
Which are surface waves?
In physics, a surface wave is a mechanical wave that propagates along the interface between differing media. A common example is gravity waves along the surface of liquids, such as ocean waves. … Elastic surface waves can travel along the surface of solids, such as Rayleigh or Love waves.
Which of the following helps to locate an earthquake epicenter?
Scientists use triangulation to find the epicenter of an earthquake. When seismic data is collected from at least three different locations, it can be used to determine the epicenter by where it intersects. Every earthquake is recorded on numerous seismographs located in different directions.
What do surface waves do?
Surface waves, in contrast to body waves can only move along the surface. They arrive after the main P and S waves and are confined to the outer layers of the Earth. They cause the most surface destruction.
Are earthquakes a surface phenomenon?
Earthquakes often cause dramatic geomorphological changes, including ground movements—either vertical or horizontal—along geologic fault traces; rising, dropping, and tilting of the ground surface; changes in the flow of groundwater; liquefaction of sandy ground; landslides; and mudflows.
How do surface waves form?
Surface waves are typically generated when the source of the earthquake is close to the Earth’s surface. As their name suggests, surface waves travel just below the surface of the ground. There are several types of surface wave, but the two most common varieties are Rayleigh waves and Love waves. …
How are earthquakes measured?
Earthquakes are recorded by a seismographic network. Each seismic station in the network measures the movement of the ground at that site. … The Richter scale measures the largest wiggle (amplitude) on the recording, but other magnitude scales measure different parts of the earthquake.
How do faults produce earthquakes?
Faults are blocks of earth’s crust that meet together. … Earthquakes occur when rock shifts or slips along fault lines Earthquakes generate waves that travel through the earth’s surface. These waves are what is felt and cause damage around the epicenter of the earthquake.
Which best explains liquefaction?
Which of the following best describes liquefaction? The transformation of stable soil into loose, liquefied material that is able to rise toward Earth’s surface. Describe how sand volcanoes form.
How does moment magnitude measure an earthquake?
The moment magnitude scale is based on the total moment release of the earthquake. … Using this scale, a magnitude 5 earthquake would result in ten times the level of ground shaking as a magnitude 4 earthquake (and about 32 times as much energy would be released).
What is the difference between moment and Richter scale?
The Richter scale is a logarithmic scale that measures the largest jolt of energy released by an earthquake. The moment magnitude scale is a logarithmic scale that measures the total amount of energy released by an earthquake.
What is Mw in earthquake?
The moment magnitude (Mw) scale, based on the concept of seismic moment, is uniformly applicable to all sizes of earthquakes but is more difficult to compute than the other types. All magnitude scales should yield approximately the same value for any given earthquake.
What are surface waves quizlet?
surface waves. seismic waves that move rock particles in a backward, rolling motion and a sideways swaying motion. strongest waves, but slowest.
Is a surface wave longitudinal or transverse?
Surface waves are neither longitudinal nor transverse. In longitudinal and transverse waves, all the particles in the entire bulk of the medium move in a parallel and a perpendicular direction (respectively) relative to the direction of energy transport. … Any wave moving through a medium has a source.
What are 3 surface waves Examples?
- Water Waves. When a person throws a heavy object such as a stone in the water, or when a person dives into a water body, ripples get formed on the water surface. …
- Seismic Waves. …
- Gravity Waves. …
- Wind Waves. …
- Electromagnetic Waves.
How do you find locate the epicenter of an earthquake?
Triangulation can be used to locate an earthquake. The seismometers are shown as green dots. The calculated distance from each seismometer to the earthquake is shown as a circle. The location where all the circles intersect is the location of the earthquake epicenter.
https://youtube.com/watch?v=6-Jr1aSHp8s
Which of the following helps to locate an earthquake epicenter quizlet?
Geologists use seismic waves to locate an earthquake’s epicenter. They measure the difference between the arrival times of the P waves and S waves. The farther away an earthquake is, the greater the time between the arrival of the P waves and the S waves.
How do you describe the location of earthquakes epicenter mountain rangers and moving plates in the Pacific Ring of Fire?
The Ring of Fire is a roughly 25,000-mile chain of volcanoes and seismically active sites that outline the Pacific Ocean. … This movement results in deep ocean trenches, volcanic eruptions, and earthquake epicenters along the boundaries where the plates meet, called fault lines.
Where do surface waves occur?
In physics, a surface wave can occur along any boundary of two different substances. The seismic type of surface wave happens at the boundary between air and rock—the surface of the earth.
https://youtube.com/watch?v=dHQMZqm_ZyI
What is velocity of a surface wave?
waves have a typical group velocity of about 3.5 km/s and can be large-amplitude arrivals on all three components of motion (vertical, radial, and transverse) out to 1000 km.
How do surface waves move during an earthquake?
Body waves can travel through the Earth’s inner layers, but surface waves can only move along the surface of the planet like ripples on water. Earthquakes send out seismic energy as both body and surface waves. The body waves (P and S) and surface waves recorded by a seismometer.
What happened to the surface during an earthquake?
Earthquakes often cause dramatic changes at Earth’s surface. In addition to the ground movements, other surface effects include changes in the flow of groundwater, landslides, and mudflows. Earthquakes can do significant damage to buildings, bridges, pipelines, railways, embankments, dams, and other structures.
What is earthquake phenomenon?
An earthquake is a phenomenon that results from the sudden release of stored energy in the Earth’s crust that creates seismic waves. … An earthquake is caused by tectonic plates (sections of the Earth’s crust) getting stuck and putting a strain on the ground.
https://youtube.com/watch?v=KW1dFiE3v-E
What do you call the area or the point on Earth’s surface directly above the focus?
The point on the Earth’s surface directly above the focus is the epicenter. When energy is released at the focus, seismic waves travel outward from that point in all directions.
What seismic waves stay on surface?
There are two major kinds of surface waves: Love waves, which are shear waves trapped near the surface, and Rayleigh waves, which have rock particle motions that are very similar to the motions of water particles in ocean waves.
What does frequency describe?
In physics, the term frequency refers to the number of waves that pass a fixed point in unit time. It also describes the number of cycles or vibrations undergone during one unit of time by a body in periodic motion.
What are the units of the Richter scale?
Richter magnitude is measured in energy (ergs): M=log10 (A/A0), where A=amplitude on a seismograph, and A0=1/1,000 millimeters. Each increase of 1 in Richter magnitude represents a 31-fold increase in the amount of released energy. Thus, a magnitude of scale-6 intensity=10×a magnitude of scale-5 intensity.
What does a seismogram measure?
A seismogram is the recording of the ground shaking at the specific location of the instrument. On a seismogram, the HORIZONTAL axis = time (measured in seconds) and the VERTICAL axis= ground displacement (usually measured in millimeters).
What is referred to as measure of the amount of energy released in an earthquake?
The moment magnitude of an earthquake is a measure of the amount of energy released – an amount that can be estimated from seismograph readings. … Richter of the California Institute of Technology, is the best known scale for measuring the magnitude of earthquakes.
How do faults produce?
A fault is a fracture or zone of fractures between two blocks of rock. Faults allow the blocks to move relative to each other. This movement may occur rapidly, in the form of an earthquake – or may occur slowly, in the form of creep. … Most faults produce repeated displacements over geologic time.
How do faults form?
Faults are fractures in Earth’s crust where movement has occurred. … It forms when rock above an inclined fracture plane moves downward, sliding along the rock on the other side of the fracture. Normal faults are often found along divergent plate boundaries, such as under the ocean where new crust is forming.
What are faults types?
Different types of faults include: normal (extensional) faults; reverse or thrust (compressional) faults; and strike-slip (shearing) faults.
What is surface faulting?
Surface faulting is displacement that reaches the earth’s surface during slip along a fault. Commonly occurs with shallow earthquakes, those with an epicenter less than 20 km. Surface faulting also may accompany aseismic creep or natural or man-induced subsidence.
Which statement best describes faults?
A fault is a fracture or zone of fractures between two blocks of rock. Faults allow the blocks to move relative to each other. This movement may occur rapidly, in the form of an earthquake – or may occur slowly, in the form of creep. Faults may range in length from a few millimeters to thousands of kilometers.
What does liquefaction mean in earthquakes?
Liquefaction takes place when loosely packed, water-logged sediments at or near the ground surface lose their strength in response to strong ground shaking. Liquefaction occurring beneath buildings and other structures can cause major damage during earthquakes.
What is the moment magnitude scale and what does it measure?
moment magnitude (MW), also called moment magnitude scale, quantitative measure of an earthquake’s magnitude (or relative size), developed in the 1970s by Japanese seismologist Hiroo Kanamori and American seismologist Thomas C. Hanks.
How do seismologists locate earthquakes?
Seismologists use the difference in arrival time between P and S waves to calculate the distance between the earthquake source and the recording instrument (seismograph). … Scientists need recordings from at least three seismographs to accurately locate the depth and magnitude of an earthquake.