Lesson 5: Mass Wasting Flashcards
It is the downslope movement of rock and regolith near the Earth’s surface
mass wasting
what force is mainly responsible for mass wasting
gravity
why is mass wasting an integral part of erosional process?
because it moves material from higher elevations to lower elevations
T of F: Mass wasting processes are occurring sporadically on all slopes; some act very slowly, others occur very suddenly, often with disastrous results.
FALSE: Mass wasting processes are occurring CONTINUOUSLY on all slopes; some act very slowly, others occur very suddenly, often with disastrous results.
Any perceptible downslope movement of rock or regolith is often referred to in general terms as a ________
landslide
during the Cherry Hills Landslide,
-how many people died?
-when did it happen?
-what type of landslide?
50 people died
on August 1-3, 1999
complex slide: started as slump, developed into debris flow near base
how many percent of the philippines is classified as highly susceptible to landslides?
80%
during the Guinsaugon Landslide in Leyte (St. Bernard)
-how many people died?
-when did it happen?
-what type of landslide?
1126 people died
on February 17, 2006
Complex side: rockslide-debris avalanche
what was thought to be the cause of the guisaugon landslide?
it rained continuously for 2 weeks and also the slope was known to be a splay of the philippine fault
during the Brgy Tinaan, Naga City, Cebu landslide
-what was the cause?
-when did it happen?
-what type of landslide?
- recent earthquakes caused groundwater to divert here & there was a fault 500m away
-Sept 18, 2018 - sinkhole collapse+ planar block slide = debris flow
Knowledge about the relationships between _________ and __________ can lead to better planning that can reduce vulnerability to such hazards
Knowledge about the relationships between LOCAL GEOLOGY and MASS WASTING PROCESSES can lead to better planning that can reduce vulnerability to such hazards
The material that is (practically) still in place and
adjacent to the highest parts of the main scarp
crown
A steep surface on the undisturbed ground at the
upper edge of the landslide
main scarp
It is the visible part of the surface of rupture.
main scarp
what causes the formation of the main scarp?
caused by movement of the displaced material away from the undisturbed ground
The highest point of contact between the displaced material and the main scarp
top
The upper parts of the landslide along the contact between the displaced material and the main scarp
head
A steep surface on the displaced material of the landslide produced by differential movements within the displaced material
minor scarp
The part of the displaced material of the landslide that overlies the surface of rupture between the main scarp and the toe of the surface of rupture
main body
The portion of the landslide that has moved beyond the toe of the surface of rupture and overlies the original ground surface.
foot
The point of the toe farthest from the top of the landslide
tip
The lower, usually curved margin of the displaced material of a landslide, it is the most distant from the main scarp.
toe
The surface that forms (or has formed) the lower boundary of the displaced material below the original ground surface
surface of rupture
The intersection (usually buried) between the lower part of the surface of rupture of a landslide and the original ground surface
toe of surface of rupture