Earthquakes

Earthquake 1

1

A break in the Earth's crust where tectonic plates have moved or are under pressure, leading to sudden slippage.

FAULT

2

The point of origin of seismic waves is called_____.

FOCUS/HYPOCENTER

3

Waves of energy produced by the fault rupture that travel outward in all directions.

SEISMIC WAVES

4

It is the point on the Earth's surface directly above the focus, which typically experiences the strongest shaking.

EPICENTER

5

Which layer of the Earth lies directly below the crust and is involved in tectonic plate movement?

MANTLE

Earthquake 2

1

A fault where two blocks slide past each other is called?

Strike-slip fault

2

In a normal fault, which way does the hanging wall move?

DOWN

3

A thrust fault is a type of what?

Reverse Fault

4

What are the giant pieces of Earth's outer layer where most earthquakes occur called?

tectonic plates

5

What type of fault occurs when the hanging wall moves downward due to tensional forces?  

Normal Fault

Earthquake 3

1

What instrument is used to detect earthquakes?

Seismograph

2

Which scale measures the energy released by an earthquake?

Richter Scale 

3

Which scale measures earthquake INTENSITY experienced by people?

Mercalli Scale

4

It is quantitative measure of an earthquake's strength.

MAGNITUDE

5

PHIVOLCS adopted a 10-point intensity scale, and it is called____.

PHIVOLCS Earthquake Intensity Scale (PEIS)

Earthquake 4

1

A Japanese term used to describe the series of ocean waves generated by the displacement of water due to underwater earthquakes or volcanic eruptions. 

tsunami

2

What mainly causes a tsunami?

• Earthquakes: Over 80% of tsunamis are caused by underwater earthquakes at converging tectonic plate boundaries.
• Landslides: Underwater or coastal landslides can trigger waves.
• Volcanic Activity: Underwater eruptions or collapses.
• Other: Rare cases include meteor impacts.

3

Refers to the downward movement of soil or rock. This happens because ground shaking can loosen rock and soil.

LANDSLIDE

4

What earthquake magnitude is usually required to generate a tsunami?

Magnitude 7.0 or higher.

5

What should you do if there's an approaching tsunami?

1.Do not stay in low-lying coastal areas after a felt earthquake. Move to higher grounds immediately.

2.If unusual sea conditions like rapid lowering of sea level are observed and unusual noise like an approaching train, plane, or whistling is heard, immediately move towards higher grounds.

3. Never go down the beach to watch a tsunami. When you see the wave, it might be too late to escape it.

4. During the retreat of sea level, interesting sights are often revealed. Fish may be stranded on dry land, attracting people to collect them. Sandbars and coral flats may also be exposed. Watching these scenes could put you in grave danger. Move away from the shoreline and quickly go to a higher ground away from the coast.

Earthquake 5

1

What is the measurement of how likely an area is to have damaging earthquakes called?

Earthquake Hazard

2

What factors increase earthquake damage?

Poor building design and soft soil.

3

When does liquefaction occur during an earthquake?

When soil loses strength due to shaking.

4

What are aftershocks?

Minor earthquakes after the mainshock

5

What is the deadliest earthquake-related hazard globally?

TSUNAMI