Environmental Geology 1010/10AM, T/Th Shaking & hot rocks Test #2, SP/1997

This is a practice exam from Spring 1997. The actual exam will have the same format, but will naturally not cover the exact same material. My suggestion is to go through this exam after you have studied the material in order to identify portions of the material covered that you might want to study more. From year to year the exact content of the course varies a bit. There may be a question or two asked in this test which we did not study. However, most of the material should look familiar. Cheers!

Matching: (Choose the best match {2 pts. each}) EQ = earthquake.

 1)____A. Wegener  A) measure of earthquake size as function of type of damage to structures,-> isoseismals
 2)____cold war  B) town covered by glowing avalanche, one survivor, Carribean subduction related
 3)____hypocenter  C) poses some seismic risk for SE NE, old reactivated rift.
 4)____Mercalli scale  D) example of strato- or composite volcano, with relatively high slope angles.
 5)____New Madrid  E) provides strength during earthquakes, spans entirety of structure without perforations
 6)____Humboldt zone  F) low for basalts relative to rhyolites, and a function of temperature
 7)____ risk  G) site where tried to control lava flow by hosing off a portion to redirect the path
 8)____ shear wall  H) generated large tsunamis that killed 10s of thousands, phreato-magmatic
 9)____ base isolation  I) ->intense geophysical exploration,e.g. global seismic network & plate tectonic revolution
 10)___ viscosity  J) large sialic eruptive center with very long eruption recurrence interval, intraplate
 11)___ Mt. Fuji  K) measure of simultaneous earthquake-volcanic energy release due to tidal forces
 12)___ Yellowstone  L) early proponent of continental drift, whose ideas were initially rejected
 13)___ Heimay, Iceland  M) reactivated continental rift, site of large intraplate EQs in 1811 & 1812
 14)___ Krakatoa  N) the product of cost & the probability of recurrence, imp. for insurance, zoning & codes
 15)___ Martinique  O) point on fault surface which rupture initiated at, location of EQ in 3-D
   P) huge shock springs or friction surface, inefficient transmittal of surface waves to structure

Diagrammatic, fill-in-the-blank and short essay:
1)
Define plate tectonics: (3 pts.)

 

2) Below is given a schematic map of fictional plate boundaries and oceanic vs. continental crust (the 2 different patterns). Use the letters on the map to identify the following locations. (5 pts.)

a) Locality where the risk of glowing avalanches (=pyroclastic flows, nuee ardentes) is greatest. __________
b) Locality where extensive basalt flows are most likely, and where earthquake frequency is less. __________
c) Locality where large EQs are expected due to a locking bend. ______________
d) Locality where larger tsunamics are most likely to be generated. ________________
e) Locality most similar to the Salton trough (Death Valley) of California. ______________

3) Various types of seismic wave exist. ______________ waves are the ones that cause significant vertical and horizontal accelerations that cause damage and loss of life. These are _________________ in velocity than _______________ waves which travel within the earth. Of these latter types of waves the ____________ wave involves deformation somewhat similar to that seen in a slinky and is the fastest, while the ____________ wave is slower and blocked by liquids. (3 pts.)

4) The __________________ magnitude attempts to measure EQ size (energy release) . It is based on the amplitude of the _____________ arrival. Since the amplitude is also a function of _________________________ in addition to EQ size, corrections must be made for this factor before a final Richter magnitude is estimated. This EQ scale was calibrated using ___________________ . (3 pts.)

5) The diagram below depicts two different fault motion histories. Use it to complete the following. (3 pts.)

a) Clearly label one line with a C for creep behavior, and the other S, for stick-slip behavior.
b) Label with 1, 2, 3 along the time (x) axis the time of the largest, second largest and third largest EQs.
c) Which history had the higher overall displacement rate (i.e. which fault is moving faster).

6) Two situations in which human activity has triggered earthquakes are: (4 pts.)

a) __________________________________________________________

b) __________________________________________________________

Which one of these has occurred in Nebraska? _____________

7) Identify which data set likely belongs to a) a slow moving plate boundary __________ b) an intraplate tectonic setting: _______________ c) a fast moving plate boundary ____________. The mathematical relationship describes what type of pattern? ________________ It can be used to compute the _________________ ____________________ for larger EQs not sampled during the relatively short time frame of human history, which is useful information in risk assessment. (4 pts.)

8) List four precursors that can be associated with dilatancy hardening and possibly used to make specific EQ predictions. (4 pts.)

a) __________________________________________

b) ______________________________________

c) __________________________________________

d) ______________________________________

Put an asterisk by the ones used in Chinese Haicheng prediction.

9) Fill out the following for an EQ case history illustrating major environmental concerns. (4 pts.)

Specific location

Year

Type of plate boundary

Associated geologic events that caused damage

Fatalities and damage estimate

10) Given the seismograph record of surface waves below answer the following. a) Which set of arrows (A,B,or C) gives information on the magnitude of ground acceleration a building will feel? ___________ b) Which set of arrows will determine if the building might reach its resonant frequency? __________ c) Which set of arrows will be a function of the type of substrate the seismograph rests on? ___________ d) Which set of arrows will be a function of fault rupture history and EQ duration? ______________ (4 pts.)

11) For the three structures or sets of structures below (A,B,C) circle the points at which you think damage from an earthquake will be concentrated, and give a reason for your choice. (3 pts.)

12) The three tectonics settings volcanism occurs in are: (3 pts.)

a) __________________________________________

b) __________________________________________

c) __________________________________________

13) Define pyroclastic (3 pts.):

 

14) An example of past enourmous fissure eruptions can be found out in Washington and Oregon and are known as the _________________ _______________ _________________ __________________ . These have a global recurrence interval on the order of ____________________ years. (2pts.)

15) Answer the following about the recent Mt. Pinatubo eruption (4 pts.)

year of eruption ________________________

size of eruption relative to Mt. St. Helens __________________

time since previous major eruption _______________

type of volcanic construct _____________________

approximate number of fatalities ____________________

height in atmosphere ash cloud went ____________

associated phenomena due to interaction with monsoons and cause of much damage and concern ___________

U.S. Agency that aided in prediction of major eruption _____________________

16) Which of the Cascade volcanoes other than Mt. St. Helens is considered to pose significant risk? _____________________________ (2 pts.)

17) We talked about the 'life cycle' certain volcanic eruptions go through. Order the below from first (A) to last (E), to give the most reasonable representation of this life cycle. (3 pts.)

________ large lateral blast, associated with glowing avalanches

________ intrusion of cryptodome, shallow magma chamber, into the stratovolcano

________ series of dome building events, and minor eruptions to build-up a stratovolcano

________ large mass wasting event on slopes of volcano

________ vertical eruption and distal transport of ash

Which mountain belt recently 'completed' this life cycle and taught geologists about a triggering mechanism?_________________

8) List three precursors to a volcanic eruption and the devices that might be used to monitor them. (4 pts.

a) ___________________________________________ __________________________________________

b) ____________________________________________ __________________________________________

c) ____________________________________________ __________________________________________

19) Below is a fictional geologic map of a volcanic center. Familiarize yourself with it and then use it to answer the following. (5 points)

a) Is there evidence of consistent past directions of lateral blasts, and if so to what direction? _________

b) Which side of the construct would you direct North-South air traffic? _______________

c) Which two rivers are most likely to see future lahars? ___________________

d) Locate with a star where you would most likely put a volcanological observatory (a base for monitoring operations) at the base of the volcano so that it would most likely survive an eruption?

e) Do you think the risk of an explosive eruption in a human life span are high or low (circle the right one) and why do you think it is high or low?

20) There is always something you studied that I didn't ask about and so this question can address this. Simply write a question that pertains to the material on earthquakes and volcanism we studied in this course. You need not answer it, only devise the question. This is not a bonus question. (4 pts.)