Chapter 6
No description yet. This curated deck is ready for daily study.
Card preview (18)
In what form are transform faults most commonly found on the ocean floor?
In offsetting spreading ridges
Are most transform faults found on land or in the ocean?
On land
The sections of transform faults that go a significant period of time without significant movement are known as what?
Seismic Gaps
Sections of transform faults that do not lock and have small, consistent earthquakes are said to what?
Creep
The San Andreas Fault begins at where on the Juan de Fuca ridge?
Trick question: it only begins after the ridge ends
Currently, unlocked portions of the San Andreas creep at what rate per year?
2cm per year
What event is known to have begun the scientific study of earthquakes? When was it?
1906, San Francisco Quake
Describe what kind of ground is most susceptible to liquification?
Bay fill and mud
When was San Francisco’s second recorded earthquake? How many died?
1989, October 17th, 62 died
Was there surface offset in the San Francisco 1989 earthquake?
No, you fool (if you got this wrong)
What is an intraplate earthquake?
An earthquake that occurs in the interiors of plates.
What happened in the winter of 1811-1812?
New Madrid, Missouri completely demolished by 3 intraplate earthquakes estimated to all be above 8.0 in magnitude
What is paleoseismology?
The study of ancient or pre-historic earthquakes.
How do paleoseismologist study earthquakes?
By using the placement of the strata within the rock.
What do we need to determine the moment magnitude of the earthquake?
• Strength of the rock involved 2.size of the fault plane 3. distance of displacement
Why do earthquakes appear where there is no boundary?
Because there were once faults in these regions but no longer (ancient rift zones)
What is it called when a rift fails to fully develop?
An aulacogen or ‘failed rift’
The failed riftzone under New Madrid is called the what?
The Reel Foot Rift.