Calculating Lag Time
(Difference in P and S Wave Arrival Times)
begin
(4) collision
of crustal47
plate
the rock
layersand data table shown below. The cro
Base your answers
to questions
andboundaries
48 on theincross
section
Time scale 0 1river2 flowing
3 4into 5the ocean.
6 7 The
8 arrows
9 10show
11 the
12direction
13 14 of15
ion shows a sediment-laden
river flow. D
(minutes
Base
your
answers
to qu
zones ofBase
sorted
sediments,
A,
B,
C,
and
D,
have
been
labeled.
Sediments
have
been
taken
from
these
zon
after
noon)
your answer to question 43 on the seismogram below. The seismogram was recorded at a seismic
recorded seismic waves from
measured.
data table
showstimes
the range
of sediment
sizes
in each
station The
and shows
the arrival
of the first
P-wave and
S-wave
fromzone.
an earthquake.
Seismogram #1
A
River
Zo
ne 1
A
B
Ocean
E
F
G
H
I
Zone
Bedrock
P-wave arrival
8:06 a.m.
8:08
B
J
Zone
XA
2
3
C
D
Ocean
Zone CS-wave arrival
Zone D
8:10
Major
1 Sediment Size
0.04 cm to 6 cm
B
0.0062cm to 0.1 cm
C
0.0004 cm to 0.006 cm
D 8:14
Less 3than 0.0004
cm
8:16
8:12
Time
4
Data Table
4
48 The
rock, siltstone,
will mos
47 How is this
pattern
of horizontal sorting pro43 Which
to the epicenter
Z sedimentary
5 of the
5part of this seismogram is used to find the distance
form from sediments deposited in zone
duced?
Y
earthquake?
(1) P-wave
time, onlysettle more
(1) A
(1) High-density
materials
6 (3) C
6 arrivalgenerally
(2) B
(4) D P-wave
slowly. (2) S-wave arrival time, only
63 State one
pos
difference in
the arrivalsettle
time ofmore
the P-wave and S-wave
arrival
(2) Rounded(3)sediments
generally
I
7
7
(4)
difference
in
the
height
of
the
P-wave
and
S-wave
bedrock
dete
slowly.
(3) Dissolved minerals are generally deposited
8
8
diagram
below is a seismogram
of the famous San Francisco earthquake of 1906, recorded
at a seisfirst.
64 Which type o
station
locatedparticles
6,400 kilometers
fromdeposited
San Francisco.
(4) Bigger
are generally
first.
II
Continent 9
9
What is the lag time?
.S./E. Sci.–Jan. ’04
last
A
B
C
D
E [12]F
G
H
I
J
65 NEXT
How long do
seismograph?
Seismogram #2
27 Which seismogram was recorded approximately 4,000 kilometers f
Arrival of
P-wave
Arrival of
S-wave
9 10 11 12 13 14 15 16 17
Arrival of
P-wave
9 10 11 1
Time (min)
T
(1)
What is the lag time?
last
Arrival of
S-wave
Arrival
of
NEXT
P-wave
Base your answers to questions 43 through 46 on the diagram and map below. The diagram shows th
eismograms of the same earthquake recorded at three different seismic stations, X, Y, and Z. The distan
B A coordinate system
A
om each seismic station toModel
the earthquake
epicenter have been drawn on Model
the map.
een placed on the map to describe locations. The map scale has not been included.
46 The difference in seismic station arrival tim
45 Model A best represents the motion of earthquake waves called
Seismograms the two waves represented by the models h
scientists determine the
(1) P-waves (compressional waves) that travel
S
(1) amount of damage caused by an earthqu
faster than S-waves P(shear waves) shown in
(2) intensity of an earthquake
model B
Station X
(3) distance to the epicenter of an earthquak
(2) P-waves (compressional waves) that travel
S bedrock
(4) timelayer
of occurrence
theD?
next earthquak
slower41than
S-waves (shear
waves)
shown
in
Approximately
how many
million
years
older
than
B is bedrock of
layer
P
model B (1) 150
(3) 340
Station
Y
(3) S-waves (shear
(2) 220waves) that travel faster than P(4) 420
waves (compressional waves) shown in modelSB
P
(4) S-waves (shear waves) that travel slower than
42 Evidence of tectonic activity in this cross section is provided by the
Base your answers to questions
Station
Z
P-waves
(compressional
waves) shown in
Earth and its interior layers. Th
(1)
folding
and
tilting
of
the
rock
layers
model B
A through D are seismic stations o
Noon
Noon
Seismogram #3
(2) faulting and movement of the rock layers
Diagram 2 shows four seismo
(3) igneous intrusion into the rock layers
A, B, C, and D during the same tim
(4) collision
of crustal47
plate
the rock
layersand data table shown below. The cross
Base your answers
to questions
andboundaries
48 on theincross
section
Time scale 0 1river2 flowing
3 4into 5the ocean.
6 7 The
8 arrows
9 10show
11 the
12direction
13 14 of15
tion shows a sediment-laden
river flow. Diffe
(minutes
Base
your
answers
to quest
ofBase
sorted
sediments,
A,
B,
C,
and
D,
have
been
labeled.
Sediments
have
been
taken
from
these
zones
after
noon)
your answer to question 43 on the seismogram below. The seismogram was recorded at a seismic
zones
recorded seismic waves from an
measured.
data table
showstimes
the range
of sediment
sizes
in each
station The
and shows
the arrival
of the first
P-wave and
S-wave
fromzone.
an earthquake.
D
E
G
H
I
Table
WhatZ are AtheBlagCOcean
times
forF stations
X, JY, Data
and
Z?
River
last
on 1
eA
2
Ocean
Zone
XA
B
Major
1 Sediment Sizes
0.04 cm to 6NEXT
cm
0.0062cm to 0.1 cm
B
be
slowly.
(3) Dissolved minerals are generally deposited
8
8
diagram
below is a seismogram
of the famous San Francisco earthquake of 1906, recorded
first.
64 W
station
locatedparticles
6,400 kilometers
fromdeposited
San Francisco.
(4) Bigger
are generally
first.
Continent 9
9
Seismogram #4
.S./E. Sci.–Jan. ’04
A
B
02:22:39
P-wave
arrival
C
D
E [12]F
G
H
I
J
65 H
se
02:26:25
S-wave
arrival
[10]
./E. Sci.–Aug. ’02
ch time scale best represents the arrival-time difference between P-waves and S-waves at th
What is the lag time?
0
P.S./E. Sci.–June ’10
P-wave
arrival
0
last
4
Time (min)
(1)
5
S-wave
arrival
0
[13]
P-wave
arrival
0
P.S./E. Sci.–August ’10
5
Time (min)
(3)
5
10
S-wave
arrival
NEXT
Time (min)
n)
on of
etters
ations
4 15 16 17
(3)
Seismogram
#5
Arrival of
P-wave
Arrival of
S-wave
Deformed rock structure like this is most often caused
(1) crustal plate collisions
(3) extrus
(2) deposition of sediments
(4) glacia
9 10 11 12 13 14 15 16 17
n)
Time (min)
25a The
seismogram
shows
seismograph
thatbelow shows the time that an
earthquake P-wave arrived(at4 a) seismic station in
mic station.
Albany, New York.
What is the lag time?
denly decreases,
last
undergoes an
26 On each
distance
Which
gradient
31 The satelliteArrival
photograph
below shows a NEXT
geologic
of
P-wave of silt, sand, and clay.
feature composed
P-wave S-wave arrival
one
possible cause
arrival
30 earthquake
During the that
Permian
Period
e
of the
resulted
in
Seismogram
#6
I
in the [1]
Appalachian Region
rock detected by this seismograph.
temperature and pressure
had
existed
in
this
environm
at a seis- P-wave
S-wave arrival
09:09:41
ich type of09:07:57
seismic wave was recorded
first on the rotatin
arrival
have formed
II
(1) schist
(2) gabbro
w long does the first S-wave take to travel from the earth
P-wave
S-wave arrival
mograph? [1]
arrival P.S./E. Sci.–June ’04
What is the lag time?
III
P-wave
arrival
IV
last
NEXT
at a seis- P-wave
S-wave arrival
ich type ofarrival
seismic wave was recorded
first on the rotatin
have
formed
Seismogram #7
II
(1) schist
(2) gabbro
w long does the first S-wave take to travel from the earth
P-wave
S-wave
arrival
09:09:41
11:40:26
mograph? [1]
arrival P.S./E. Sci.–June 11:47:31
’04
III
What is the lag
IV
station?
last
P-wave
time? arrival
[14]
49 No P
(1) P
NEXT
Time (min)
Tim
(1)
Seismogram
#8
Arrival of
S-wave
Arrival of
P-wave
on the diagrams below. Diagram 1 represents a cross section of
( ) shows the location of an earthquake epicenter. Letters
urface.
eled I, II, III, and IV, which were recorded at seismic stations
9 10 11 12 13 14 15 16 17
Arrival of
P-wave
Deformed rock
(1) crustal plate
(2) deposition o
9 10 11 12
Time (min)
Tim
Earthquake
25a The
seismogram
below sh
through 65 on
the
diagram
below,
which
shows
seismograph
that
epicenter
( seismic
2)
earthquake P-wave arrived
uake
located
4000
kilometers
from
this
station.
A
Albany, New York.
What is the lag time?
Diagram 1
Weight
D
28 When the velocity
of a stream suddenly decreases,
Pen being transported undergoes an
the sediment
last
increase in
31 The satellit
feature com
NEXT