MIDTERMS Flashcards
- True or False: Man-made structures must be at least 5 meters away from a known active fault trace to be considered safe from ground rupture?
True
- How many active volcanoes are there in the Philippines?
24
- It is a situation where the probability of injury, mortality, or damaged properties to an area or population in a specific period is reduced at a level that is relatively safe following the establishment of one or a combination of mitigation measures.
Acceptable risk
- True or False: Incremental geologic processes cannot trigger large-scale disasters.
False
- These are maps that show the level to which an area or population is exposed or at risk to a specific geological hazard.
Geological Hazard Map
- It is a geochemical classification which groups the chemical elements according to their preferred host phases (i.e., lithophile-silicate loving; siderophileiron loving; chalcophile- sulfur loving; and atmophile- gas loving)
Goldschmidt geochemical classification
- True or False: An electronegativity difference of lesser than 1.68 indicates that the chemical bonding undergone by a mineral or compound is dominantly covalent.
False
- It is a mantle convection model that contends that there exists two largely disconnected convective layers i.e., a dynamic upper layer driven by descending slabs of cold oceanic lithosphere and a sluggish lower layer that carries heat upward without appreciably mixing with the layer above.
Layer Cake Model
- Continental crusts have an average silica concentration of ______________ ppm.
60,000ppm or 60%
- It is a statement that a high probability of a hazardous event is imminent based on a forecast.
Warning
- t is a line Bureau of the Department of Environment and Natural Resources which is responsible for the rational administration and disposition of mineral lands and resources, development of mining, geological, metallurgical, chemical and related technologies thru basic and applied researches, and inventory of mineral resources. This agency conducts studies related to raininduced landslide, flooding, ground subsidence, and coastal hazards.
Mines and Geosciences Bureau
- It is an aspect of vulnerability that refers to the ability of a population to cope and/or prepare to the impacts of a particular hazard.
Adaptive Capacity
- It is the degree or inability to resist to the effects/impacts of hazard or to respond when a disaster has occurred.
Vulnerability
- What are five most common geological hazards in the Philippines?
- Typhoons
- Earthquake
- Volcanic Eruptions
- Tsunami
- Mass wasting
- What does the acronym PAGASA and PHIVOLCS stand for, respectively?
PAGASA - Philippine Atmospheric Geophysical and Atmospheric Services Administration
PHIVOLCS - Philippine Institute of Volcanology and Seismology
- These are zones of earthquake hypocenters where there is a planar zone of seismicity which is inferred to correspond with the down-going slab in a subduction zone.
Wadati-Benioff zone
- How long was the ground rupture that manifested during the Luzon 1990 magnitude 7.8 earthquake? The ground rupture transected from Dingalan, Aurora to Kayapa, Nueva Vlzcaya as a result of strike-slip movements along the NW segment of the Philippine Fault Zone and its splay, the Digdig Fault.
125 km-long
- True or False: Deformation involves dilation
and distortion.
True
- These are surface waves that move the ground from side to side in a horizontal plane but at right angles to the direction of propagation
Love Waves
- Give at least two difference between conventional and alternative geophysical methods to study earthquakes and/or map faults
Conventional - costly, can cover a larger area, intrusive
Traditional - Cost effective, specific area,
- It is the approximate maximum depth to
which earthquakes can occur.
More than 670km
- He is a Scottish geologist who authored the The Dynamics of Faulting and Dyke Formation with Application to Britain (Edinburgh, 1942, 1951) and systematized our knowledge of the geometry and stress fields of various faults. He contended that the direction of the maximum principal stress along normal faults is ________.
Ernest Masson Anderson; vertical
- Low-rise buildings have __________________ period compared to high-rise buildings.
shorter
- It is a phenomenon where sand/silt-rich strata behave in a fluid-like manner in response to strong ground shaking.
Liquefaction
- Strong earthquakes have magnitudes ranging from ________ to __________.
6.0-6.9
- It is a branch of seismology concerned with the offsets in sedimentary strata proximal to fault zones to determine probable recurrence intervals of major earthquakes prior to historical records.
Paleoseismology
- It refers to the remaining country rock material at the site of melting. It usually occurs during the production of granite and is composed predominantly of mafic minerals.
Restite
- What is the average silica concentration of magmas expelled from active volcanoes in the Philippines?
52% to 68%
- True or False: Basaltic lavas that solidify at near-surface conditions may produce vesicle-bearing to scoriaceous textures.
False. Basaltic Magma
- It is a pyroclastic material composed of 45% lithic lapilli, 20% lithic ash, and 30% vitric bombs.
Tuff-Breccia
- What are the two sub processes of magmatic assimilation process?
- Stopping
- Shouldering
- True or False: Andesitic magmas that generate more evolved granitic magmas are considered primary magmas.
False
- What are the factors that influence the degree of explosiveness of a volcano?
a. Silica Content
b. Temperature
c. Amount of dissolved gases
- The Mt. Pinatubo eruption triggered up to a __________ degrees Celsius drop in global temperature.
0.25
- It is a relative measure of the explosiveness of volcanic eruptions. It is classified based on the volume of erupted tephra
Volcanic Explosivity Index (VEI)
- What type of volcanic hazard caused majority of the casualties following the eruption of the Mt. Krakatau in Indonesia?
Tsunami
- True or False: Tsunamis have shorter wavelengths compared to wind-generated waves due to their high wave velocity
False
- When did the Mw 8.1 Moro Gulf Earthquake and Tsunami occurred? What specific tectonic feature generated the earthquake?
August 17, 1976
- When did the 9.2MW Good Friday Earthquake in Alaska happened?
March 27, 1964
- It is a phenomenon where the apex of a tsunami wave reaches the coast first.
Run-up
- Formula for wave amplitude
1/2 of wave height
- Formula for wave base depth
1/2 wavelength
- It is a phenomenon where the trough of a tsunami wave reaches the coast first.
Drawdown
- Calculate the wave base and wave amplitude if (1) the total distance between three consecutive wave crests is 400 meters and (2) average distance between succeeding wave crests and troughs is 40 meters.
wave base = 100m
wave amplitude = 20m
- It is a Japanese-derived term which literally means “harbor wave”
Tsunami
- True or False: Tsunamis achieve their highest velocity and wave height along ocean basins and near coastlines, respectively.
False or true
- True or False: Ophiolite obduction may have triggered tsunami events.
True
- Enumerate at least four (4) processes that can trigger a tsunami.
- Volcanic Eruption
- Undersea Landslide
- Earthquake
- Meteor Impact
- The December 24, 2004 Indian Ocean Tsunami was triggered by what magnitude earthquake along the oceanic trench off the coast of Sumatra, Indonesia?
9.1Mw
- What triggered the March 27, 1964 Good Friday earthquake in Alaska?
a. Caused deformation of the crust where huge blocks
where dropped down as much as 2.3 m
b. Sediment accumulating in the trench slumped into
the trench and generated a tsunami
- What GIS tool allows the extraction of specific elevation values for tsunami inundation modelling?
Raster Calculator
- These are coalesced dolines.
–
- It is the slowest type of mass movement.
Creep
- These are materials that are still in place and adjacent to the highest parts of the main scarp.
Crown
- A steep surface on the undisturbed ground at the upper edge of the landslide, caused by movement of the displaced material away from the undisturbed ground. It is the visible part of the surface of rupture.
Main Scarp
- It is a process involving the detachment of soil or rock from a steep slope and the more or less free and extremely rapid descent of the material.
Fall
- It is defined as the lowering of the land surface due to sinkhole development.
Subsidence
- What are the two types of slides?
- Rotational Slide
- Transitional Slide
- What is the difference between mass wasting and erosion?
Mass wasting is a component of erosion
- Landslides are what specific type of mass movement?
Mass wasting
- These are weathered in-situ hillslope materials.
Regolith
- These are commonly used to anchor loose rocks to more massive, solid bodies of rock; applicable on areas that have highly fractured rocks are exposed on steep slopes and where weakness planes are inclined in the same direction as the slope.
Rock Bolts
- When did the Cherry Hills Landslide
occurred?
August 1-3, 1999
- What are the ions produced during the interaction of calcite and carbonic acid?
Ca+2HCO
- It is the part of a landslide that marks the farthest point that the slid mass has reached.
Tip
- What are the specific mass movement types that occurred during the Guinsaugon Landslide in 2006?
Complex slide (rockslide-debris avalanche)
- The likelihood of ground subsidence in areas to be developed that are underlain by highly fragmented limestone can be reduced/mitigated by what means?
Grouting
- It is a term referring to stream-sink or point/s at which a stream disappears underground. These features are typical in karstic areas.
Sinkhole
- Concavo-convex landslides can be
represented in plan view as:
circles with outside and inner lines
- It is an institutional planning tool developed by Department of Environment and Natural Resources (DENR) through Administrative Order No. 28, series of 2000 (DENR AO 2000-28) on March 2000 to safeguard development projects from the hazards caused by geological phenomena.
Geohazard Assessment and Mapping Program
- It is the part of a landslide that has formed in the lower boundary of the displaced material below the original ground surface
Surface of Rupture
- What is the range of slope values for gently sloping to undulating topography, based on DENR’s slope classification category?
3 to 8
- These features form in an analogous manner to subjacent karst-collapse dolines, with a blanket of superficial deposits or thick soil being washed or falling into widened joints and solution pipes in the limestone beneath.
–
- True or False: In the context of triggering mass wasting events, frictional resistance and slope have an inverse correlation.
True
- True or False: The factor of safety is the ratio
of the allowable stress to the actual stress: A
factor of safety of 1 represents that the stress is
at the allowable limit. A factor of safety of less
than 1 represents likely failure. A factor of
safety of greater than 1 represents how much
the stress is within the allowable limit.
True
- What is the difference between a high vs. very high landslide susceptible area?
High - inactive
Very high - recent landslide
- What GIS tool is used to delineate concave, convex, and flat areas?
Curvature
- How does pore pressure influence ground subsidence? What are the processes that may alter the subsurface pore pressure?
Pore pressure maintains the ground level;
Change in the level or volume of groundwater.