Earthquakes can cause frustrating and frightening moments in people's lives. Yet this is very common to planet earth, and has been that way since the beginning of time. Here are your vocab words to look for:

*Normal fault – A fault that forms at a divergent boundary.  It is when a hanging black and the football block are converging together in a vertical motion. Another term for a dip-slip fault.​

*Reverse fault - The opposite of a normal fault. The two plates will diverge away from each other.​

*Compressional stress – A force that squishes material.​

*Tensional stress - A force that stretches material .​

*Thrust fault – Another name for a strike-slip fault. A layer of old rock is place on top of the new layer of rock.​

*Transform fault - The horizontal slip between tectonic elements.​

*P-wave – Also known as primary waves, can travel through solids, liquids, and gases. It's the fastest wave and its compressible  Material movement is in the same direction as the wave movement.​

*S-wave - Also known as secondary waves, they are slower than P-waves. They can travel through only solids, they also share waves, so the material moves perpendicular to wave movement.​

*Intensity – Describes the perceived surface ground shaking and damaged caused by an earthquake. Its also derived based on ground accelerations as measured by seismographs.​

*Seismograph - When an earthquake happens, its recorded and identified according to 3 types of waves that can be generated. The first 2, P-waves and S-waves are waves that happen in the earth's inner layers. Reyleigh and love waves happen on the earth's crust. There's a box and a pole with string and a weight on it. When the earthquake hits, the pendulum will start moving and will move accordingly to the movement of the earthquake.​

*Epicenter – The point of the earthquake where the seismic waves are received from the focus and transmit them to a location.

*Focus - The starting point in which earthquakes originate from.

*Moment magnitude – Was created by two CalTech seismologists; Dr. Hiroo Kanamori and Tom Hanks in 1977. It is a successor to the Ritcher scale, having a 1-10 scale, it measures the magnitude of an earthquake, but in a different way. It's used to compare the energy released in an earthquake.

*Richter scale - The Ritcher magnitude scale was created to measure an earthquake's magnitude. The scale was created by Charles Ritcher. Ranges from 1-10, but this scale measures the magnitude of an earthquake. Scientists would normally use this scale.

*Mercalli Scale – The Mercalli scale is responsible for the intensity of an earthquake. It ranges from 1-10 just like the Ritcher scale, but this scale has descriptions of what people would see in an earthquake. Was created by 

*Aftershock - Is a tremor or a shake that would happen after an earthquake. Fore shocks happen before an earthquake happens.

*Liquifaction – When material becomes liquid, and this process will happen in a landslide. 

*Tsunami - A long high sea wave of disturbance. This can usually happen after an earthquake, if the magnitude is strong enough to make water currents happen. It can also be referred to as a "harbor wave" in Japanese.

*Accretionary wedge - When a plate subducts, the top layer of the plate that the continental and oceanic crust collide, will have sediments scraped off on top of the undergoing oceanic crust.

*Asthenosphere - Its a layer in the earth where it's below the lithosphere and the crust of the earth.

*Moho Discontinuity – A layer of the earth where it's located between the lithosphere and asthenosphere.

*Surface Wave - Surface waves include love waves and Reyleigh waves. These waves happen at the surface of the earth.

*Strike-slip – When two plates suddenly slip in a vertical motion/path.

*Wavelength - The length of a wave.

*Velocity – The direction in the speed the earthquake is going.

*Shaking - A tremor on the earth's lithosphere/crust that can activate an earthquake.

*Hazard – Dangerous zones or areas in an earthquake or any type of disaster.

*Earthquake - When the tremor happened at the focus and spreads from the epicenter to a location.

*Shadow zone – When a seismograph cannot detect S and P-waves in a certain area.

*Lithosphere - The crust of the earth. The layer of earth where we can be able to walk on.

*Hypocenter – It's the epicenter of an earthquake. Both these names are interchangeable.

*Landslide - When the process of liquification is in play. It will swallow up everything in its path.

*Geomorphology – The study of earth and it's formations overtime.

*Frequency -  How often an earthquake occurs.

*Displacement – The change in the plates over a certain amount of time.

*Deformation - Breaking material down in various processes.

*Benioff Zone – A seismic zone in the oceanic zone, where subduction of lithospheric plates give rise from frequent earthquakes. It's marked by ocean trenches that slop 45 degrees downward.

*Bedrock - rock that is embedded under the crust that we walk on.





Steps for an Earthquake to Happen:

 

1) There's a strike - slip with the earth's tectonic plates.



2) All of the energy that is concentrated at the focus will spread to the epicenter/hypocenter.



3) When the energy of seismic waves is delivered to the epicenter/hypocenter, then from there, the seismic waves will be carried out to a location that will receive the damage.



4) Once the energy hits a city or town, there's a tremor at the crust which the ground will appear to be moving along with many things within the town or city.

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5) After the earthquake if there's a strong magnitude, will have aftershocks that can last a while.





An earthquake will happen when there is a sudden movement or shaking of the earth's lithosphere, which contains the crust and the upper mantle. Two plates will rub against each other in a sideways motions. That's right, this is a transform boundary! We go through a couple hundred earthquakes a year, they are too weak to be felt.