Geology Reference
In-Depth Information
Exercise 8 • Landslides and Avalanches
125
8.
According to gradient, is the potential for landslide greater
at X or K? Explain.
18.
Why have the utility lines been placed above ground on
the west side of Boulder Drive?
19.
Money and resources are still being used to make this
landslide region habitable. What short-term and long-term
solutions to the community's problems might be appropriate?
9.
What is the material labeled "Qal" on the map? (Q is an
abbreviation for Quaternary, a geologic period.)
10.
What are the two ways in which Qal is formed (see
description)?
20.
On Figure 8.15 (1963), outline three major landslides.
Hint: Use the maps (Figures 8.12 and 8.14) showing areas of
movement or damage for clues.
11.
Locate the deposit Qaf. What is it?
21.
Are there landslides on Figure 8.16 (1993) that did not
appear on the 1963 stereopair? If so outline them.
These deposits are becoming more common as humans con-
tinue to alter the landscape. Some geologists use the term
anthropogenous deposits for these materials.
22.
Mark two areas of additional houses and one other cul-
tural feature that appear in the 1993 photo that are not on the
1963 photo.
12.
Review the drawing of the mudflow in Figure 8.2. Observe
the topography shown on Figure 8.12, and mark with "X" as
two areas that might be subject to mudflows. Explain your
decisions. (Hint: See Colluvial deposits on the explanation for
Figure 8.12.)
a.
23. Using a colored pencil draw the contact between the base
of the mountain and the alluvial fan on which San Jose is
built. What is the approximate elevation of this line (com-
pare with the map, Figure 8.13 in the back of the manual or
Figure 8.12)?
b.
13. a.
How far (in feet) is Noble School from a landslide deposit
or an area of damage from landslides (refer to Figures 8.12
and 8.14).
24. a.
What advice would you give to those seeking a build-
ing site in the mountain area?
b. As a consulting geologist, what advice would you give
to the local zoning commission in this area?
b. Are any schools on or closer to mapped landslides?
14.
Would you expect a landslide to develop under Noble
School? Explain.
PART C. LANDSLIDES IN ATHENS, OHIO
Landslides in Athens, Ohio, are representative of those
throughout much of the Appalachian Plateau Physio-
graphic Province. They include many of the types of
mass wasting listed in the Introduction to Exercise 8.
The most common types in Athens and southeastern
Ohio are slump-earthflow, rock falls, and rockslides.
Recognition of geomorphic features of landslide
deposits (see Part A) is important if we are to avoid
potentially hazardous sites and understand the
processes of change in the landscape. In this exercise
we investigate, using a series of photographs, the
changes in an apartment complex constructed in the
1960s adjacent to the Hocking River near Ohio Univer-
sity. Study the indicated aerial photographs and maps
and Table 8.2 to answer the questions.
15.
Note that a road in the subdivision had to be abandoned.
What road was extended to accommodate the traffic?
16.
In what subdivision are the badly damaged and aban-
doned houses?
17.
Would you purchase a house on the north side of Boulder
Drive, east of Sophist Drive (see Figures 8.12 and 8.14)?
Explain.
