Quarter 2: Lesson 2

Question 1

is a ground movement on a
sloping terrain.
➢ If rain or any source of water
frequently flows down a
sloping area, the
gravitational descent of
loosened soil makes it
possible for landslide to
occur.

Answer 1

Landslides

Question 2

very slow downslope movement
of particles that occurs in every

slope covered with loose,
weathered material

Answer 2

Soil Creep
Landslide

Question 3

when the slope
becomes saturated
with water, this then
triggers a landslide

Answer 3

Debris Flow
Landslide

Question 4

sudden slides caused by
heavy rain the rock on
the slope loosens and
then slides down the

slope.

Answer 4

Rock Fall landslides

Question 4

downward movement of
rock debris, usually the
consequence of removal of
buttressing earth at the
foot of a slope of
unconsolidated material

Answer 4

Slumping Landslide

Question 5

A topographic depression

created when

groundwater dissolves
the underlying limestone
bedrock. Known as “sink”

or “doline”.

Answer 5

Sinkhol

e

Question 6

➢ Develop when water slowly
erodes the rock below the
surface, creating a void.
➢ Over time, the soil above
collapses into the empty space,
causing a sudden and often
catastrophic sinkhole at the
surface.
➢ Guatemala City Sinkhole
(2010) – a dramatic collapse
sinkhole caused by a
combination of volcanic pumice
beneath the surface and heavy
rain from Tropical Storm Agatha.

Answer 6

Cover Collapse

Question 7

➢occur when sand or loose
material on the surface
gradually trickles into voids
in the bedrock below,
causing a slow depression
over time.
➢They are less dramatic and
form more slowly compared
to cover-collapse sinkholes.

Answer 7

Cover
Subsidence

Question 8

Such types of sinks
may be caused by
various human
activities, including
groundwater pumping

and building.

Answer 8

Artificial Sinkhole

Question 9

1. occur where there is little
   soil or vegetation over the
   soluble rock.
2. Aggressive dissolution
   occurs where flow is focused
   in pre-existing openings in the
   rock , such as along joints,
   fractures, and bedding planes,
   or in the zone of water – table
   fluctuations where the ground
   water is in contact with the
   atmosphere.
3. typically develop gradually.

Answer 9

Dissolution
Sinkhole

Question 10

Multiple landslide events
within the same place
● Inspecting an area of an old
landslide for scarps and
deposits is a clear indicator
that a landslide will
reactivate.

Answer 10

Earlier landslide as indicator

Question 11

Caused by the stress and
friction produced by
geologic materials
moving apart
● These cracks are located
on higher elevated
ground.

Answer 11

Tension cracks

Question 12

The most common of these
is that trees are bending up
in a J-curve as a sign that
the ground slips
● Creaking and cracking can
also be warning signs. This
motion can be slow or rapid.

Answer 12

Things Moving

Question 13

Changes in water flow.
● A debris flow is a very wet,
very mobile landslide, where
water is loaded with trees,
mud, rock, and everything
else caught in the current.

Answer 13

Water Doing
Something Different