Brainscape's Knowledge GenomeTM


Top Flashcards (Certified)
All Flashcards

GEOLOGY > GEOLOGICAL PRINCIPLES > Flashcards

GEOLOGICAL PRINCIPLES Flashcards

1
Q

What forms the bedrock of safe and sustainable civil engineering?

A

Geological knowledge

Understanding seismic hazards and groundwater dynamics is crucial for civil engineering.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
2
Q

What are the critical intersections between geology and civil engineering discussed in the report?

A

Earthquake genesis and hydrological prospecting

These aspects have implications for infrastructure resilience.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
3
Q

What modern technique integrates real-time groundwater monitoring to address liquefaction risks?

A

Seismic retrofitting techniques

This approach enhances disaster mitigation strategies.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
4
Q

What advances allow precise mapping of fault zones beneath urban centers?

A

Geophysical imaging

This represents a paradigm shift from reactive to proactive disaster mitigation.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
5
Q

How many seismic events does the Philippines experience daily?

A

20+ seismic events

This is due to its dynamic tectonic setting.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
6
Q

What tectonic plates converge in the Philippine Archipelago?

A

Eurasian, Philippine Sea, and Indo-Australian plates

This convergence creates a seismogenic powerhouse.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
7
Q

What is the width of the Philippine Mobile Belt?

A

300 km-wide

It is a zone of intense crustal deformation.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
8
Q

What is the northwestward motion of the Philippine Sea Plate relative to Sundaland?

A

8-10 cm/yr

This motion drives megathrust earthquakes and strike-slip faulting.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
9
Q

What is the role of the Philippine Mobile Belt?

A

Acts as a buffer between tectonic plates

It facilitates interactions between subduction systems.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
10
Q

True or False: The Philippine Archipelago is located in a tectonically stable region.

A

False

It is one of Earth’s most dynamic tectonic intersections.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
11
Q

Fill in the blank: The Philippine Mobile Belt is a zone of intense crustal deformation bounded by opposing _______.

A

subduction systems

This defines the geological dynamics of the region.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
12
Q
A
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
13
Q

What does the Philippine Mobile Belt act as a buffer between?

A

• Manila Trench (West)
• Philippine Trench (East)
• Cotaboato Trench (South)

These trenches involve different types of subduction interactions.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
14
Q

What is the rate of subduction of the Eurasian Plate beneath Lu20n?

A

2-5 cm/y

This subduction forms the Lu20n Volcanic Arc.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
15
Q

What is the depth of the Philippine Trench?

A

10,540 m

This makes it the Earth’s third deepest trench.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
16
Q

What type of boundary is the Cotaboato Trench?

A

Collisional boundary

It accommodates convergence through thrust faults.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
17
Q

What is the convergence rate accommodated by the Cotaboato Trench?

A

4 cm/yr

This rate is significant for seismic activity in the region.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
18
Q

What geological features manifest from the E-W compression at S-? kPa/yr?

A

• Uplifted coral terraces in Bondoc Peninsula
• Folding of Miocene limestone into anticlines beneath Metro Manila
• Oblique-slip mechanisms along the Philippine Fault Zone

These features illustrate the effects of tectonic compression.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
19
Q

What is the length and width of the Philippine Fault Zone?

A

1,200 km length, 5-40 km width

This structure plays a critical role in accommodating tectonic stress.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
20
Q

What percentage of oblique Philippine Sea Plate convergence transfers to trench-normal subduction?

A

70%

This highlights the dynamics of the subduction process.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
21
Q

What percentage of the convergence manifests as strike-slip along the Philippine Fault?

A

30%

This reflects the movement dynamics along the fault.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
22
Q

What are the GPS vectors indicating about slip rates near Leyte and Mindanao?

A

22 mm/yr slip near Leyte vs 35 mm/yr in Mindanao

This indicates increasing strain accumulation towards the south.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
23
Q

What is the recurrence interval for M?+ earthquakes along the Philippine Fault?

A

200-400 years

This is influenced by the fault’s segmented structure.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
24
Q

What is the thickness of the accretionary wedge in the Manila Trench?

A

8 km thick

The accretionary wedge is characterized by a 3° dip angle and is prone to shallow thrust events.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
25
What magnitude events can the locked megathrust in the Manila Trench potentially generate?
M8.3 events ## Footnote It extends 150 km downdip and has a co-seismic slip of 6-8 m based on coral microatoll data.
26
What type of eruptions are correlated with the slab depth of 120-180 km in the Manila Trench?
Andesitic eruptions ## Footnote Mayon Volcano's eruptions exhibit SiO₂ content of 58-63%.
27
At what rate is the Philippine Trench propagating southward?
50 mm/yr ## Footnote The trench is classified as young, being less than 9 million years old.
28
What is the dip angle of the Benioff zone in the Philippine Trench?
45°W ## Footnote This geometry limits deep seismicity to less than 150 km depth.
29
What does the duplex structure at 50-70 km depth in the Philippine Trench suggest?
Slab dehydration embrittlement ## Footnote This is related to the double seismic zone observed in the trench.
30
What tsunami risk was associated with the 2017 M6.5 Surigao earthquake?
Generated 2 m waves ## Footnote This was caused by splay fault activation.
31
What is the length of the West Valley Fault (wVF) in Metro Manila?
100 km long ## Footnote It has a magnitude capability of M7.2 with a recurrence interval of 400 years.
32
What vertical offsets were revealed in paleoseismic trenches in relation to the West Valley Fault?
2-4 m vertical offsets ## Footnote These offsets are found in Holocene alluvium.
33
What is the potential impact of an M8.2 scenario from the Manila Trench Megathrust?
Induce 0.89 PGA ## Footnote This is particularly concerning for reclaimed areas like Parañaque.
34
What is the N₁ value in coastal districts like Pasay and Navotas?
Less than 10 ## Footnote This indicates the need for stone column densification due to liquefaction risks in saturated Holocene sands.
35
36
37
What is Base Isolation in the context of seismic design?
Base Isolation involves using lead-rubber bearings to withstand seismic shaking. ## Footnote Example: San Beda College retrofit used 120 lead-rubber bearings (K=1.2 kN/mm) to withstand 0.69 shaking.
38
What is the purpose of Fault Setbacks according to PHIVOLCS?
Fault Setbacks mandate a 10 m exclusion zone from active fault traces. ## Footnote This is challenging for developments in fault-crossing areas like Baguio.
39
What type of tsunami barriers are employed at Matina Coast in Davao?
8 m-high seawalls with energy-dissipating tetrapods are used. ## Footnote Tetrapods are 35-ton units designed to absorb wave energy.
40
What was the magnitude and impact of the 1990 Luzon Earthquake?
Magnitude 7.8; caused $364M damage, 78% of collapsed buildings had soft-story weaknesses. ## Footnote The earthquake was caused by the Philippine Fault rupture.
41
What geological event characterized the 2013 Bohol Earthquake?
A blind thrust reactivation tilted the Chocolate Hills 5 degrees, exposing limestone bedrock. ## Footnote The earthquake had a magnitude of 7.2.
42
What was notable about the 2023 Masbate Earthquake?
It had a magnitude of 6.6 and involved strike-slip motion along an offshore segment. ## Footnote This generated 5 cm of co-seismic uplift.
43
What does the volcanic activity of Mayon in 2018 reveal about volcano-tectonic interplay?
Mayon's 2018 eruption (VEI 3) coincided with 142 M3+ earthquakes from magma-induced stress transfer. ## Footnote Engineers must integrate real-time SO2 monitoring into evacuation protocols.
44
What is the rate of sea level rise and its impact on tsunami inundation in Manila?
Sea level rise is 3 mm/year, exacerbating tsunami inundation depths by 12-18% per RCP8.5. ## Footnote RCP8.5 refers to a high greenhouse gas concentration scenario.
45
Fill in the blank: The 1990 Luzon Earthquake had a magnitude of _______.
7.8
46
True or False: The 2013 Bohol Earthquake resulted in the tilting of the Chocolate Hills.
True
47
What role does real-time SO2 monitoring play in civil engineering during volcanic eruptions?
It is integrated into evacuation protocols to ensure public safety. ## Footnote Monitoring thresholds are set at 10-20 kt/day.
48
What is the rate of sea level rise that exacerbates tsunami inundation depths in Manila?
3 mm/yr ## Footnote This subsidence increases inundation depths by 12-18% per RCP8.5.
49
What extreme weather event triggered 1,200 landslides in Leyte's fault-weathered schists?
Typhoon Jolina (2021) ## Footnote This event highlights the impact of extreme weather on geological stability.
50
What type of sensing network detects microtremors along EDSA?
Fiber Optic Sensing ## Footnote The 150 km DAS network has a strain sensitivity of 10-6.
51
What system issues alerts 10-40 seconds before seismic shaking in the Philippines?
PHIVOLCS' Terra system ## Footnote It uses Bayesian source inversion for early warning.
52
What are continental plates?
Massive, rigid slabs of rock that form the Earth's continents ## Footnote They are thicker and less dense than oceanic plates.
53
What are oceanic plates?
Large, rigid slabs of rock that form the ocean floor ## Footnote They are thinner and denser than continental plates.
54
What is the asthenosphere?
A hot, soft layer of the mantle beneath tectonic plates ## Footnote It acts like a giant, slow-moving conveyor belt.
55
How do tectonic plates move?
They are dragged by currents in the asthenosphere ## Footnote These currents are caused by heat from Earth's core.
56
Fill in the blank: Continental plates are _______ and less dense.
thicker
57
Fill in the blank: Oceanic plates are _______ and denser.
thinner
58
What are the three types of plate boundaries?
Convergent, Divergent, Transform ## Footnote These boundaries describe the movement and interaction of tectonic plates.
59
What happens at convergent boundaries?
Plates collide or come together ## Footnote This can lead to geological phenomena such as mountain formation, volcanic activity, and earthquakes.
60
What geological phenomena can result from convergent boundaries?
* Mountain formation * Volcanic activity * Earthquakes ## Footnote These phenomena occur due to the interactions of colliding tectonic plates.
61
What is the movement of plates at divergent boundaries?
Plates move away from each other ## Footnote This movement leads to the creation of new crust.
62
What is created at divergent boundaries?
New crust as magma rises from the mantle ## Footnote The magma solidifies and forms new oceanic crust.
63
What role do divergent boundaries play in Earth's geology?
Responsible for continuous reshaping and formation of Earth's crust ## Footnote This process is essential for the dynamic nature of the planet's surface.
64
What is the movement of plates at transform boundaries?
Plates slide past each other ## Footnote This sliding motion can lead to earthquakes.
65
________ occur when two plates slide past each other horizontally. The movement along these boundaries can cause earthquakes, as the plates grind against each other.
Transform Boundaries
66
When continental plates collide (e.g., the Himalayas).
Convergent
67
When the plates rub each other (e.g. San Andreas Fault).
Transform
68
Where new oceanic crust forms. (e.g. Mid-Atlantic Ridge).
Divergent

GEOLOGY (6 decks)

Brainscape helps you reach your goals faster, through stronger study habits.
© 2025 Bold Learning Solutions. Terms and Conditions