SNOW
HYDROLOGY (GEOG 4321/5321): HOMEWORK ASSIGNMENT 4
Instuctor: Mark Williams
Telephone: 492-8830
TA: Qinghuan Zhang
Email: qinghuan.zhang@colorado.edu
Homework 4
Assigned February 10.
This assignment will be due Monday, February 15, to be turned into by 5 pm.
Late assignments will be penalized 5% per day. No work will be
accepted after 2pm on Wednesday
40 possible points.
Please box all your quantitative answers.
Please show all your work! Answers without work will only receive
partial credit.
- Draw a schmatic diagram of a slab avalanche, label the various
parts, and also label where these forces are most likely to be found:
tension, compression, and shear. (5 points)
- Why are small gullies called terrain traps with respect to
avalanche danger? Be sure to address in your answer: slope angle,
exposure, wind, runout zones, and lack of perceived danger. (5 points)
- Calculate the shear stress in N/m2 in a snowpack given the
following parameters:
- density = 250 kg/m3; snow height = 1 meter; and slope
angle
= 30 degrees.
- Change the slope angle to 45 degrees. What is the shear
stress? What is the precentage change in the shear stress caused by the
increase in slope angle?
- Do the same calculation as in b, but increase snow density
and snowpack depth: density = 450 kg/m3; snow height = 2.5 meter; and
slope angle = 45 degrees. What is the shear stress? What is the
precentage change in the shear stress caused by these changes compared
to problems a and b? (10 points)
- The local forecast states that a recent storm has deposited
champagne powder on the Continental Divide: 1 meter of new snow with a
density of 80 kg/m3. You and a group of friends have decided to head
out into the
backcountry and put first tracks on a great bowl near Berthoud Pass,
which has an angle of 40 degrees. Before leaving Boulder, the wind
picks up and is blowing 20 m/s. Describe how you would use this
information to decide which slopes to ski. Once you arrive at Berthoud
Pass, what other steps might you take to evaluate the stability of the
slope before skiing? One page maximum. (10 points)
- Explain why, where, and how a Rutschblock test is conducted
(10 points)