Nature & distribution Flashcards
What is the focus?
point at which pressure is released
What is the epicentre?
point immediately above the focus
Characteristics of a shallow focus?
0-70km deep
cause the most damage
account for 75% of earthquake energy released
Characteristics of an intermediate focus?
70-300 km deep
Characteristics of a deep focus?
300-700 km thick
Where do the vast majority of earthquakes occur?
along plate boundaries with the most destructive being at a destructive margin
What is the boundary marked by at a conservative plate boundary?
fault line
What is the richter scale?
logarithmic scale used to measure an event
What is the energy released?
proportional to the magnitude so that for each unit increase on the scale, the energy released increases by 30 times
What dose the moment magnitude scale identify?
energy release
What does the mercalli scale measure?
intensity of an event and its impact
