Geohazard Flashcards
(130 cards)
1
Q
A weak to violent shaking of the ground produced by the sudden movement of rock materials below the earth’s surface
A
Earthquake
2
Q
Movement caused by forces deep within the earth’s interior
A
Earthquake
3
Q
Origin of earthquake
A
- Volcanic Activity
- Tectonic Activity
4
Q
The origin of an earthquake occurs at depths between ____ and ________ km at the focus
A
5 and 700 km
5
Q
A number that characterizes the relative size of an earthquake
A
Magnitude
6
Q
The reading or graph produced to read the magnitude
A
Seismogram
7
Q
The machine that records the magnitude
A
Seismograph
8
Q
Scales used in measuring magnitude
A
- Richter Magnitude/ local magnitude (ML)
- Surface-wave magnitude (Ms)
- Body-wave magnitude (Mb)
- Moment of magnitude (Mw)
9
Q
A quantitative measurement that relies on data gleaned from seismic records to estimate the amount of energy released at an earthquake source
A
Magnitude
10
Q
Describing the severity of an earthquake in terms of its effects on the earth’s surface and on humans and their structures
A
Intensity
11
Q
Used to measure the earthquake’s intensity
A
Modified Mercalli Scale
12
Q
The point on the earth’s surface vertically above the focus of an earthquake
A
Epicenter
13
Q
The location where the earthquake begins
A
Focus / Hypocenter
14
Q
It is released during an earthquake
A
Seismic Waves
15
Q
Small Tremors that follows strong earthquakes, sometime they are stronger than the actual quake
A
Aftershock
16
Q
Gradually diminish in frequency and intensity over a period of several months
A
Aftershock
17
Q
Small earthquake that precede a major earthquake by days or in some cases year
A
Foreshock
18
Q
Magnitude of 1986 Casiguran Earthquake
A
Ms 7.3
19
Q
Magnitude of 1973 Ragay Gulf Earthquake
A
Ms. 7.0
20
Q
Magnitude of 1976 Moro Gulf Earthquake
A
Ms. 7.9
21
Q
Magnitude of 1983 Laoag Earthquake
A
Ms 6.5
22
Q
Magnitude of 1990 Luzon Earthquake
A
Ms 7.8
23
Q
Magnitude of 1990 Bohol Earthquake
A
Ms 6.8
24
Q
Magnitude of 1990 Panay Earthquake
A
Ms 7.1
25
Magnitude of 2002 Sultan Kudarar Earthquake
Ms 6.8
26
Magnitude of 2003 Masbate Earthquake
Ms 6.2
27
Magnitude of 2012 Negros Earthquake
Ms 6.9
28
Magnitude of 2012 Guiuan, Eastern Samar Earthquake
Ms 7.6
29
Magnitude of 2013 Bohol Earthquake
Ms. 7.2
30
Magnitude of 2017 Batangas Earthquake
Ms 5.5 Earthquake Swarm
31
Magnitude of 2017 Jaro, Leyte Earthquake
Ms 6.5
32
Magnitude of 2017 Nasugbu, Batangas Earthquake
Ms 6.2
33
Year of the Ms. 7.3 Casiguran Earthquake
1968
34
Year of the Ms. 7.0 Ragay Gulf Earthquake
1973
35
Year of the Ms. 7.9 Moro Gulf Earthquake
1976
36
Year of the Ms. 6.5 Laoag Earthquake
1983
37
Year of the Ms. 7.8 Luzon Earthquake
1990
38
Year of the Ms. 6.8 Bohol Earthquake
1990
39
Year of the Ms. 7.1 Panay Earthquake
1990
40
Year of the Ms. 6.8 Sultan Kudarar Earthquake
2002
41
Year of the Ms. 6.2 Masbate Earthquake
2003
42
Year of the Ms. 6.9 Negros Earthquake
February 2012
43
Year of the Ms. 7.6 Guiuan, Eastern Samar Earthquake
August 2012
44
Year of the Ms. 7.2 Bohol Earthquake
October 2013
45
Year of the Ms. 5.5 Batangas Earthquake
April 2017
46
Year of the Ms. 6.5 Jaro, Leyte Earthquake
July 2017
47
Year of the Ms. 6.2 Nasugbu, Batangas Earthquake
August 2017
48
Earthquake Preventive Measures
1. Seek Shelter under stable table or under door frames
2. If outside, stay away from buildings, bridges and electricity pylons and move to open areas
3. Avoid areas at risk from secondary processes, such as landslides, rockfall and soil liquefaction
4. After an earthquake, check gas, water and electricity pipes and lines for damage
5. Listen to the radio and follow the instructions issued by the authorities
49
A process by which water-saturated sediment temporarily loses strength and acts as a fluid when you wiggle your toes in the wet sand near the water at the beach
Liquefaction
50
Ensure that the structure has ductility, the ability to accommodate large deformations and adjustable supports to correct against differential settlements of the soil
Building Liquefaction Resistant Structures
51
Increasing the density and/or improving the drainage characteristics of liquefiable soil reduce liquefaction hazards by limiting increases in water pressure within the soil during and earthquake
Soil Improvement Techniques
52
A technique in which a vibrating prove is used to penetrate the soil up to a depth of 100 feet and the vibration of the probe caused the grain structure surrounding probe to collapse and consequently increase in density. The soil is then probe in a grid like pattern to achieve densification of the soil in a given area
Vibroflotation
53
This method involves using gravel to backfill the wells created by the probe
Vibro-Replacement
54
The process by which geologic materials are moved downslope from one place to another without a transport agent such as wind or water
Mass Wasting
55
Major Causes of mass Wasting
1. Slope
2. Fluid
3. Vegetation
56
The __________ the slope the greater the downslope pull
Steeper
57
__________________ tend to support only very low- angle slopes
Dry unconsolidated materials, smooth and rounded particles
58
____________________ can be piled more steeply without becoming unstable
Rough, sticky or irregular particles
59
________ reduces friction
fluid
60
for _______________, a little water present may add cohesion but large increase in water leads to instability
Unconsolidated materials
61
________________ tends to stabilize slopes
Vegetation
62
Guinsaugon Landslide happened on
February 17, 2006
63
A massive rock slide debris avalanche occurred in the province of Southern Leyte, causing widespread damage and loss of life
Guinsaugon Landslide
64
Official death toll of Guinsaugon landslide
1,126
65
caused of Guinsaugon Landslide
10 day period heavy rain and a 2.6 earthquake
66
Mass wasting Preventive Measures
1. Reduce Slope Angles to create Stability
2. Reduce additional weights on unstable slopes
3. Enhance vegetative cover to stabilize slopes
4. Reduce moisture contents of materials through improved drainage
5. Shotcreting, coconet, masonry wall
67
An unusually large sea wave produced by a seaquake or undersea
Tsunami
68
Is a series of sea waves commonly generated by under-the-sea earthquakes and whose could be greater than 5 meters
Tsunami
69
It is sometimes mistakenly associated with storm surges
Tsunami
70
can occur when the earthquake is shallow-seated and strong enough to displace parts of the seabed and disturb the mass of water over it
Tsunami
71
Some Natural Signs of an Approachable to Tsunami
1. A felt earthquake
2. Unusual sea level change: sudden sea water change
3. Rumbling sound of approaching waves
72
An overflow of water that submerges that submerges land that is usually dry
Flooding
73
Covering by water of land not normally covered by water
Flooding
74
_____________ Defines flood as a covering by water of land not normally covered by water
European Union (EU) floods Directive
75
Flood Preventive Measures
1. Permanent monitoring of the risk of flooding
2. Setting up one or several information and flood warning centers for the population especially with regard to large capacity hydraulic dams
3. Issuing regulations banning building, residing in, and access to identified risk zones and implementing specific protective systems such as alarm signals
4. Building and developing infrastructure that will prevent, avoid or limit floods and protect the population
5. Planning the evacuation of the population likely to be at risk and instructing them on how to behave in case of a flood
6. Forming well trained and equipped management and rescue teams
7. Lowering water levels in hydraulic dams and increasing the flow of rivers
76
Is the motion of a surface as it shifts downward relative to a datum such as sea level.
Subsidence
77
The opposite of subsidence, which results in an increase in elevation
Uplift
78
Causes of Subsidence
1. Oil/ Natural Gas Extraction
2. Mining
3. Dissolution of Limestone
4. Groundwater - Related
79
Subsidence Preventive Measures
1. Remove trees and bushes planted near the house. Trees are one of the most common causes of subsidence as the roots withdraw moisture from the soil supporting the foundation
2. If you cannot remove the trees, maintain them with regular pruning. This should curb their growth and limit their search for water close to the house
3. Carry out regular inspections of your property, paying particular attention to pipework, gutters and drainage systems in case of leaks and/ or blocks
4. Stiffening of panels and foundation to promote rigid body structural movements
5. Loosening of connections between structural members and at foundation locations to allow some extend of mechanism movements
6. Tying members and foundations to provide temporary resistance to tensile and shear deformations
7. Excavating around foundations to make them more flexible and to promote ground cracks away from them
80
Occurs when waves and currents remove sand from the beach system
Beach Erosion
81
Beach Erosion Preventive Measures
1. Sand must be trucked in from other sources and filtered for sediments
2. Build seawalls, revetments and jetties along the shoreline
82
volcanoes erupted within the last 10,000 years based on analyses of datable materials
Active Volcanoes
83
Volcanoes erupted within historical times (within the last 600 years), accounts of these eruptions were documented by man
Active Volcanoes
84
Volcanoes which is morphologically young - looking but with no historically records of eruption
Potentially Active Volcanoes
85
Volcanoes which has no record of eruption; physical form is being changed by weathering and erosion via formation of deep and long gullies
Inactive Volcanoes
86
Volcanic Phenomena directly associated with eruption
1. Lava flow, dome growth
2. Pyroclastic flow, pyroclastic surge, lateral blast
3. Tephra fall - ash fall, volcanic bomb
4. Volcanic gas
87
Volcanic Phenomena indirectly associated with eruption
1. Lahar, flooding
2. Debris Avalanche, Landslide
3. Tsunami, seiche
4. Subsidence, Fissuring
5. Secondary/ Hydrothermal Explosion
6. Secondary Pyroclastic flow
88
A highly elongated mass of molten rock materials cascading downslope from an erupting vent.
Lava Flow
89
The lava flow being extruded has ___________________ contents.
low silica and low water
90
A pile or mound of lava that grew on the floor of an active crater, on the side slopes via feeder vent that breached through the surface of the edifice, or inside the volcanic edifice
Dome Growth
91
Hot dry masses of fragmented volcanic materials that move along the slope and in contact with ground surface
Pyroclastic Flow
92
Pyroclastic Flow includes
1. pumice flow
2. ash flow
3. block and ash flow
4. nuee ardente
5. glowing avalanche
93
Turbulent low-concentration density currents of gases, rock debris and in some cases, water, that move above the ground surface at high velocities
Pyroclastic Surge
94
Arises when pent-up gases facilitate their way out through the impermeable overlying materials and cause a very rapid escape into the atmosphere
Hot Blasts
95
Blasts that are __________________ often do much damage and could exact a high toll in human lives
Directed obliquely
96
Combination of pyroclastic flows and pyroclastic surges with an especially strong initial laterally-directed thrust
Lateral Blasts
97
Lateral Blasts have an initial velocity of (1) ______ kph and slow down to about (2) _______ kph near its margin (3) _____ km from the volcano
1. 600 kph
2. 100 kph
3. 25 km
98
Consists of pumice, scoria, dense lithic materials or crystals or combination of the four
Tephra Falls
99
One of the basic components of a magma or lava
Volcanic Gas
100
Volcanoes may release to the atmosphere gases
Volcanic Gas
101
Sometimes called mudflows or volcanic debris flow
Lahar
102
Flowing mixtures of volcanic debris and water
Lahar
103
Lahar associated directly with volcanic eruption
Primary or Hot Lahar
104
Lahar caused by heavy rainfall
Secondary or Cold Lahar
105
Fast downhill movement of soil and rock caused by slope failure on the cones of stratovolcanoes
Debris Avalanche
106
Explosions from instantaneous flashing of steam upon contact with hot rocks
Hydrothermal Explosions
107
Caused by the contact of water with hot pyroclastic flow deposits
Secondary Explosions
108
first 5 Precursors of an Impending Volcanic Eruption
1. Increase in the frequency of volcanic quakes with rumbling sounds; occurrence of volcanic tremors
2. Increased steaming activity ; change in color of steam emission from white to gray due to entrained ash
3. Crater glow due to presence of magma at or near the crater
4. Ground Swells (or inflation), ground tilt and ground fissuring due to magma intrusion
5. Localized landslides, rockfalls and landslides from the summit area not attributable to heavy rains
109
Last 5 Precursors of an impending Volcanic Eruption
6. Noticeable increase in the extent of drying up of vegetation around the volcano's upper slopes
7. Increase in the temperature of hot springs, wells and crater lake near the volcano
8. Noticeable variation in the chemical content of springs, crater lakes within the vicinity of the volcano
9. Drying up of spring/ wells around the volcano
10. Development of new thermal areas and/or reactivation of old ones; appearance of solfataras
110
Long term patterns or Trends of Meteorological conditons
Climate
111
The meteorological conditions in a given place on a given day
Weather
112
Refers to the increasing changes in the measures of climate over a long period of time including precipitation, temperature and wind patterns
Climate Change
113
Refers to the rise in global temperatures due mainly to the increasing concentrations of greenhouse gases in the atmosphere
Global Warming
114
What Causes Climate Change?
1. Strength of the Sun
2. Milankovitch Cycle
3. Greenhouse Gases
4. Ocean Currents
5. Plate Tectonics and Volcanism
6. Change in Land Cover
7. Meteorite Impacts
115
River Affected by the Marcopper Mining Disaster 1996
Boac River, Marinduque
116
When did Marcopper Mining Disaster occurred?
March 24, 1996
117
Company responsible for Placer, Surigao del Norte Disaster?
Manila Mining Corp
118
When did the Placer, Surigao Del Norte Disaster Occurred?
July 9, 1987
September 2, 1995
April 26, 1999
119
When and where Philex Mine Wastes Spill Occurred?
When: August 1, 2012
Where: Padcal Mine
120
When did the Semirara Coal Mine Collapse Occurred?
February 13, 2013
121
When and where did the Mt. Diwalwal Gold Rush happened?
When: Started in 1980
Where: Brgy. Diwalwal, Monkayo, Compostela Valley
122
Company responsible for the Rapu-rapu Cyanide Spill?
Lafayette Philippines Inc.
123
When and where did the Rapu- rapu Cyanide Spill happened?
When: July 11, 2007
Where: Rapu-Rapu Albay
124
When and where did the TVI Pacific Inc. Incident happened?
When: Nov. 22, 2004
Where: Siocon, Zamboanga Del Norte
125
Company responsible for Sipalay Incident?
Maricalum Mining Corp
126
When and where did the Sipalay Incident happened?
When: 1982 and 2001
Where: Sipalay, Negros Occidental
127
When and where did the Magnetite Mining happened?
When: 2008 (started date)
Where: Cagayan
128
How many company is responsible for Magnetite Mining?
10 black sand mining companies
129
When and Where did the Bre-X Scandal happened?
When: March 19,1997
Where: Busang, Indonesia
130
Person Responsible for Bre-X Scandal?
Michael de Guzman
