Earthquakes - SECONDARY EARTHQUAKE HAZARDS

Question 1

primary hazard associated with earthquakes

Answer 1

failure of structures

Question 2

secondary earthquake hazards

Answer 2

liquefaction
ground displacement
ground fissures
earthquake-induced mass wasting
fires
tsunamis

Question 3

what sediment is prone to liquefaction

Answer 3

sand

Question 4

what is liquefaction

Answer 4

compacted sand-rich sediments behave like a fluid due to lateral/shear motion

Question 5

what causes liquefaction

Answer 5

lateral motion increasing the water pressure within pore spaces, preventing vibrating grains from making contact with each other

Question 6

rocks on either side of a fault move away from each other horizontally or vertically

Answer 6

ground displacement

Question 7

are large open cracks that typically develop near the surface

Answer 7

ground fissures

Question 8

ground fissures are developed near the surface where there is little resistance to ______ and _____

Answer 8

rolling and stretching motion

Question 9

t or f: open fissures affect less number of structures than faults

Answer 9

F (affect more because they occur over a much broader area)

Question 10

t or f: earthquake trigger mass wasting

Answer 10

t

Question 11

gas lines are broken and ignited by broken electrical wires in damaged buildings

Answer 11

fire

Question 12

a series of ocean wave that is formed when energy is suddenly released and transferred into the ocean

Answer 12

tsunami

Question 13

tsunamis are triggered usually by _____ faulting

Answer 13

thrust

Question 14

italian seismologist who created an intensity scale

Answer 14

Giuseppe Mercalli, 1902

Question 15

quantifies earthquakes through first-hand human observations of the damage sustained by buildings

Answer 15

intensity scale

Question 16

rankings on intensity scale are _____ and ____ such that similar rankings are grouped together

Answer 16

plotted on a map ; contoured

Question 17

what is PEIS

Answer 17

PHIVOLCS Earthquake Intensity Scale

Question 18

PEIS was developed as a response to what particular event?

Answer 18

1990 Luzon Earthquake (Mag 7.8)

Question 19

PEIS replaced what intensity scale on what year?

Answer 19

Rossi-Forel intensity scale on 1996

Question 20

one of the first seismic scales used to reflect earthquake intensities and was used for about two decades until the introduction of Mercalli scale

Answer 20

Rossi-Forel intensity scale

Question 21

who developed Rossi-Forel intensity scale?

Answer 21

Michele Stefano de Rossi and Francois Alphonse Forel in the late 19th century

Question 22

PEIS ranges from

Answer 22

I to X

Question 23

PEIS

Answer 23

scarcely perceptible
slightly felt
weak
moderately strong
strong
very strong
destructive
very destructive
devastating
completely devastating

Question 24

quantify the amount of ground shaking and energy released of earthquakes

Answer 24

Magnitude Scales

Question 25

Richter Magnitude Scale was named after

Answer 25

Charles F. Richter

Question 26

Richter magnitude scale rates earthquakes based on _______

Answer 26

the size of their seismic waves

Question 27

what measures the size of seismic waves

Answer 27

seismograph

Question 28

the size of seismic waves is governed by its:

Answer 28

amplitude (wave height) and distance

Question 29

scientists discovered that Richter magnitude scale isn't always consistent with one another, particularly for ______

Answer 29

large-magnitude earthquakes

Question 30

t or f: moment magnitude scale is based on the similar types of seismogram measurements as Richter's

Answer 30

T

Question 31

why is moment magnitude more accurate than richter's?

Answer 31

because it covers a wide range of geological conditions and magnitude

Question 32

the total amount of energy released of earthquake based on moment magnitude scale is determined by:

Answer 32

the surface area of the ruptured fault and the vertical/horizontal displacement

Question 33

a magnitude 7 earthquake is how many times stronger than magnitude 4 in terms of ground shaking

Answer 33

1000x

Question 34

a magnitude 7 earthquake is how many times stronger than magnitude 4 in terms of energy released

Answer 34

27,000x

Question 35

san francisco earthquake

Answer 35

1906, Mag 7.8

Question 36

loma prieta earthquake

Answer 36

October 17, 1989 (Mag 6.9)

Question 37

indonesian earthquake

Answer 37

December 24, 2004 (Mag 9.1)

Question 38

classification of earthquakes based on magnitude

Answer 38

great 8 or more major 7-7.9 strong 6-6.9 moderate 5-5.9 light 4-4.9 minor 2-3.9 micro 1.0-1.9

Question 39

Abra earthquake

Answer 39

July 27, 2022 (Mag 7.0)

Question 40

in terms of frequency _____ to _____ types of earthquake magnitude often occur

Answer 40

micro to minor

Question 41

Moro Gulf Earthquake

Answer 41

August 17, 1976 Mag 8.1 depth: 59km along cotabato, near sulu trench 12:11 AM generated a 4.5 km tsunami

Question 42

Japan earthquake that caused liquefaction

Answer 42

Niigata, Japan (1964) magnitude 7.5

Question 43

Taiwan earthquake

Answer 43

1999 , Mag 7.6