Lab 12-2
docx
keyboard_arrow_up
School
Oklahoma State University *
*We aren’t endorsed by this school
Course
1114
Subject
Geography
Date
Dec 6, 2023
Type
docx
Pages
13
Uploaded by MateTarsierPerson933
Name: __________________________
FALL 2023
Laboratory Investigation 12
Earthquakes and Volcanic Eruptions
PART 2
3. QUESTIONS
3.1
(L1)
What is the
epicenter
of an earthquake?
(0.5 pt)
3.2
(L1)
What are the differences between the Mercalli and Richter scales?
(0.5 pt)
3.3
(L1)
What are the main causes of most earthquakes occurring currently in Oklahoma,
Kansas, and Texas?
(0.5 pt)
3.4
(L1)
What is the
Volcanic Explosivity Index
(VEI)?
(0.5 pt)
3.5
(L1)
Name the typical volcano type found in the Hawaiian Islands.
(0.5 pt)
GEOG 1114 Lab
12. Earthquakes and volcanic eruptions
4. PRACTICE AND APPLY YOUR KNOWLEDGE
Searching Earthquake databases
Any time you feel an earthquake or think you felt an earthquake you can go and check
the USGS database of earthquakes. They usually have maps that show earthquakes
recorded in the US and the world in the past day, 7 days or 30 days. You can also go
back in time and search for earthquakes you felt personally.
In this exercise we will explore the most recent earthquakes in the US.
Open the link:
https://www.usgs.gov/programs/earthquake-hazards
One of the features you will find is the Earthquake Interactive Map. Click on it and you
will see the earthquakes in the US during the past day.
Then zoom out and you will see the whole world. You will see the locations of the
earthquakes in the past day. The image below is from November 9, 2023.
You will notice that most earthquakes occur near or on the red lines. Those red lines are
the plate boundaries.
On the left you will see a list of earthquakes with information about the event such as
time, magnitude, and location.
For this exercise we will search for some recent earthquakes in the United States.
Go to the search page:
Search Earthquake Catalog (usgs.gov)
2
GEOG 1114 Lab
12. Earthquakes and volcanic eruptions
Under Basic Options select earthquakes of magnitude “+2.5,” for time and dates select
“past 30 days,” and for Geographic Region select “Conterminous U.S.” Then,
and click
on “search.”
Then, a map with white and colored circles will appear.
Now go to the upper right corner and open the “basemap and overlays” icon
(
).
Select “street”, so you see the state boundaries on the map. Make sure that the boxes
“plate boundaries” and “U.S. Faults” are checked.
Then, also on the upper right side of the map, find the key icon (
), and click on it.
The legend of the map will appear. Analyze the symbols. Magnitude is represented by
circle size. The color of the circle refers to time of the event within the specified time
frame (30 days). Thus, the circles on the map are the epicenters of earthquakes
registered the last 30 days.
Go back to the map and click on any circle.
A box like the one below will pop up on the
left side.
3
Your preview ends here
Eager to read complete document? Join bartleby learn and gain access to the full version
- Access to all documents
- Unlimited textbook solutions
- 24/7 expert homework help
GEOG 1114 Lab
12. Earthquakes and volcanic eruptions
This box has the basic information about that earthquake, including magnitude (2.9 in
this case), time, location and depth of the hypocenter (or focus). The blue rectangle
showing the roman numeral is the intensity (in this case is II). If it says DFYI (Did you
feel it?) it indicates that it is based on reports that people in the area submitted.
If you click on the DYFI rectangle, you will be prompted to a page with more information
on this quake, including a more detailed map, and the number of reports from nearby
residents submitted.
The intensity II in the figure above is an estimation or a number based on a report that
someone in that area gave based on observations according to the
Mercalli Intensity
Scale
(see Table 2.1, page 109 of the handbook). However, if this earthquake
happened in your area and you contact them with information on damage or type of
shaking, they will adjust the magnitude. Thus, if enough data exist, they will update it.
You can also get this box of information by clicking on a particular earthquake listed on
the right side of the map. You can change the list by magnitude and by time of
occurrence.
Also, on the map, the plate boundaries appear in red. Notice that most of them are in
the western part of the country.
Now answer the following questions:
4.1
(L2)
In what part of the conterminous US do you see the highest concentration of
earthquakes in the past 30 days?
Name the region(s) or state(s).
(1 pt)
4.2
(L1)
Is the area you answered in question 4.1 near a plate boundary? (
0.5 pt)
4
GEOG 1114 Lab
12. Earthquakes and volcanic eruptions
4.3
(L1)
In what parts of the country (states or regions) do you see clusters of earthquakes
that are not
near tectonic plate boundaries?
(0.5 pt)
4.4
(L2)
Go to the list of earthquakes (right-hand side) and find the highest magnitude
earthquake registered in the past 30 days in the contiguous 48 United States. Fill out
the following information:
(2 pts)
Date and time:
Location:
Coordinates of the epicenter:
Depth of the hypocenter (focus):
Intensity:
Magnitude:
4.5
(L2)
Zoom on Oklahoma and find the most recent earthquakes in the state of
Oklahoma during past 30 days.
Then, choose the earthquake with highest magnitude
and answer the questions below
(2 pt)
Location:
Date and Time:
Magnitude:
Intensity:
5
GEOG 1114 Lab
12. Earthquakes and volcanic eruptions
4.6
(L2)
Click on the magnitude box (DYFI), then on the new page find the DYFI (Did you
feel it?) products. Then, you will see a map with squares of different colors indicating
locations where people reported the earthquake on this website. How many responses
from residents for this particular earthquake in the following location?
What was the
intensity reported at each of these locations
(0.5 pt)
4.7
(L2)
Watch footage of a magnitude 7.1 earthquake in California (July 2019).
https://www.youtube.com/watch?v=_Y11iyK2te8
Then, using the Modified Mercalli Scale (page 109 in the handbook) assign a
number to this earthquake.
(1 pt)
Locating the epicenter of an earthquake using trilateration
This exercise explores how data from seismographs in different locations can be used
to pinpoint the epicenter of an earthquake using seismograph data (See Figures 12.1-
12.2) using the trilateration method (Fig. 12.3 in handbook).
4.8
(L4)
First, fill in the table below with the required data using the charts in the appendix
at the end of this lab.
(3 pts)
Station
P-wave arrival
time
(seconds)
S-wave arrival
time
(seconds)
P- minus s- waves
arrival times
(seconds)
Distance to
epicenter from
station (kilometers)
Marlow, OK
Carrier, OK
Bolivar, MO
4.9
(L4)
Using the procedure you learned from the video, determine the location of the
epicenter on the map provided using the trilateration method on the map below.
(2 pts)
6
Your preview ends here
Eager to read complete document? Join bartleby learn and gain access to the full version
- Access to all documents
- Unlimited textbook solutions
- 24/7 expert homework help
GEOG 1114 Lab
12. Earthquakes and volcanic eruptions
Identifying volcanic hazards during a simulated eruption
7
GEOG 1114 Lab
12. Earthquakes and volcanic eruptions
The map of Figure 4.1.1 shows a map of the area immediate around
Pacaya Volcano
in
Guatemala. A separate jpeg (
Pacaya.jpeg
) is included in the Canvas module, if you prefer
to use it for better resolution. You have the scale and north arrow as references.
Figure 4.1.1 Pacaya Volcano (Guatemala) and its surroundings.
Pacaya Volcano (Volcán Pacaya) is in the same region as
Fuego Volcano
, the one you
read about on pages 116-119 of the handbook. Therefore, the effects of the eruptions of
the two volcanoes are expected to be similar over their surroundings.
Pacaya is a
composite volcano
, so in case of eruption, you may expect high explosivity.
Now we will simulate an eruption for an exercise.
The simulated event has a VEI of 4. The calculation of the VEI and the dominant winds
indicate that the area affected by ash fall will be about 10 km away from the volcano.
The time of the eruption is during the
wet season
.
Lava flows will only cover areas to the south as far as 4 km. However, pyroclastic flows
will develop due to rains and possibly lahars should flow down along the main valleys
reaching distances as far as 7 km from the volcano.
4.10
(L4)
Now, identify on the map the three villages around the volcano: Santa Elena
Barillas, San Vicente Pacaya, and Palin. Now, based on the information above, you
will assess the types of volcanic hazard that threat each of the villages. In the table
below, mark with an an “x” if the village is threatened by each of the three volcanic
hazards.
(1.5 pts)
Village
Downwind ashfall
Lava flows
Lahars
8
GEOG 1114 Lab
12. Earthquakes and volcanic eruptions
Santa Elena Barillas
San Vicente Pacaya
Palin
Explain your answers for each of the volcanic hazards in a sentence or two.
(1.5 pts)
Pyroclastic flows:
Lava flows:
Downwind ashfall:
Points
Section 3:
Section 4:
Total:
____________ out of 18 points
9
Your preview ends here
Eager to read complete document? Join bartleby learn and gain access to the full version
- Access to all documents
- Unlimited textbook solutions
- 24/7 expert homework help
GEOG 1114 Lab
12. Earthquakes and volcanic eruptions
Appendix: Seismographs and P-S Wave Graphs
Marlow, OK, Seismograph.
10
GEOG 1114 Lab
12. Earthquakes and volcanic eruptions
Carrier, OK Seismograph.
11
GEOG 1114 Lab
12. Earthquakes and volcanic eruptions
Bolivar, MO Seismograph.
12
Your preview ends here
Eager to read complete document? Join bartleby learn and gain access to the full version
- Access to all documents
- Unlimited textbook solutions
- 24/7 expert homework help
GEOG 1114 Lab
12. Earthquakes and volcanic eruptions
Seismic wave arrival graph.
13