Lesson #2 - Earthquakes Flashcards
Types of Earthquakes:
- Originate within 60km (40 miles)
- majority earthquake focci are shallow
Shallow eathquakes
Types of Earthquakes:
- 12% of total energy released by earthquakes
- focal depth 60- 300 km
Intermidiate earthquakes
Types of Earthquakes:
- 700 (430 miles)
- occur in Benioff Zones + Subducting Slab
- dip averages in 45 degrees
- creates trench
Deep Focal earthquake
- It’s a zone of EQ concentration associated with subducting ocean slabs.
- It exists only on the boundaries that have trenches
- Evidence of plate interactions
Benioff Zone
Convergence of plates:
Oceanic plate + Oceanic Plate =
Volcanic Island Arc
Convergence of plates:
Oceanic plate + Continential Plate =
Volcanic Arc
- A fault where movement or slippage is expected to occur
- Mark certain areas that are broken to earthquakes
- Clear Breaks and the soil ears from the surface down the bottom
Active fault
- Fault that has seized Activity for a long time
- Do not disturb or break all the layers of the soil
Inactive fault
We can say that the fault is active if?
- If there is observed movement of evidence of seismic activity during the last 10,000 years
The shaking of the earth’s surface resulting from the sudden release of energy
Earthquake s
Give the four notable fault systems in the philippines (4 main & 2 sub)
1) Guinayangan Fault
2)Masbate fault
3) Vigan-Aggao Fault
4) Marikina Valley Fault System
- East Valley Fault
- West Valley Fault
Fault Lines:
1) GF - Active fsult transversing province central portion, and is also part of the PFZ
- Cause of 7 Mw
Guinayangan Fault
Fault Lines:
2) MF - Considered a seismically active region in the country, which explains the frequent quakes in the area
- Cause of 6.6 Mw
Masbate Fault
Fault Lines:
3) V-A F — Located in the western most part of the fault line in the philippines
Vigan-Aggao Fault
Fault Lines:
4) MVFS - One of the most well known and feared fault lines in the philippines.
a) EVF - 10 km long (7.2 Mw)
b) WVF - 100 lm lonv (could trigger the “Big One”)
Marikina Valley Fault System
a) East valley fault
b) West valley Fault
If you are living in the areas near the active fault what should you do?
Go beyond duck, cover and hold,
Retrofit Your house, create a disaster plan, and put together an emergency kit
This type of earthquake comes before the main shock
Fore shock
This type of earthquake Comes after the main shock
After shock
This type of earthquake is a sequence of seismic waves and does not have a main shock (happenes in a short period of time)
Swarm
Where the movement or the earthquake took place
Hypocenter
Directly above the hypocenter
Epicenter
Elevated surface caused by the movement of the fault
Fault Scarp
