Earthquakes Flashcards
When do earthquakes happen
Happens when the crust is solid and only 100 miles off the epicenter
What is the after shock
Tremors that happen after the main earthquake
Give 3 facts about shallow depth earthquakes
Found at all boundaries, Less than 80km deep, Very powerful, Short warning
Give 3 facts about deep earthquakes
Found at subduction, Not as powerful, Longer warning
Where do earthquakes occur
80% Ring of Fire, Mostly convergent margin activity, 15% at mediteranen-Asiatic belt, 5% in the interior of plates
How many earthwquakes are recorded each year
> 150,000
When do earthquakes occur (2)
When the crust is solid and only about 100 miles off the surface
Give 3 facts about primary waves
Fast, Moves through solid rock, pushes and pulls the rock
What are compression waves
Waves that push and pull through rock
Give 2 facts about secondary waves
Slower and move at right angles
What are the 3 movements of surface waves
Love and Rayleigh, Love goes side to side, Rayleigh up and down
What are the 3 P’s
Prediction, Planning and Preventing
Who are people that study earthquakes
Seismologists
What 2 principals are Earthquakes predicted on
Seismic gaps and earthquake zones
Where are seismic gaps located
Fault lines
What is an ancient way of a warning system and give an example
Behavior of animals, Tianjin city (7.4)
What gas can be released before an earthquake
Radon gas
What are the 3 most used scales for earthquakes
Richter, MMS and Mercalli scale
How many tsunami sensors are located on the sea floor
6
How many seismographs gather information
3
What is the primary effect of earthquake destruction
Ground vibrations
What are the 4 secondary effects of earthquake destruction
Liquefaction, landslides and avalanches, fires, tsunamis
What are the 4 level of effects of earthquake destruction influenced by
Distance from epi-center, Magnitude of EQ, Construction quality, Geology rock type
What is Liquefaction
When soft sediments begin to move due to seismic waves
What City is subjected to Liquefaction and why
Mexico because it sits on an old lakebed
Give 3 things you can plan ahead for incase of an earthquake
store food and batteries, Warning sirens or drills, flexible gas or power lines
Give 3 things you can do to your building to limit damage during an earthquake
Stepped foundation, Use reinforces concrete, Shutters over windows
