Geology Short Answer Questions
- Understand the hazard
- Determine the risk from that hazard for the region of interest
- Determine ways to reduce risk
- Do a cost-benefit analysis
- Implement mitigation techniques if warranted
Discuss how we assess the seismic risk in an area.
- Locate and determine nature of the hazard in the area
- Study history of that hazard
- Determine geologic/geographic factors in the area
- Determine potential human interactions with the hazard in the area
Discuss the measure we need to take to minimize damage from seismic activity in an earthquake-risk
- Apply land use zoning
- Apply stringent building codes
- Attempt to predict earthquakes
What are the three main factors that determine whether a landslide will occur or not?
- Rock material
Rocks can have joints. What are three things that can cause joints?
- Release of pressure when rocks come to surface
- Squeezing of rocks
- Shrinking of igneous rocks
What are the two main criteria used to name igneous rocks?
- Grain size
When magma comes out of the ground, it will be in one of these two forms:
- Pyroclastic material
Ethical framework for carrying out ESE require us to work towards two goals:
What is the difference between porosity and permeability?
- Porosity: ability to absorb water
- Permeability: amount of liquid that can seep through
What is the difference between mafic igneous rocks and felsic igneous rocks?
- Mafic: low viscosity, dark,
- Felsic: high viscosity, light
What is the difference between normal faults and reverse faults?
- Draw dip slip and reverse dip slip, pressure arrows Explain plate tectonics.
- Plate tectonics explains how crustal plates move around the surface of the earth and allows
geologists to find explanations from geological events such as earthquakes and volcanoes.
The crust of the earth is separated into 10 major plates and a few smaller ones. There are 3
motions of plates: convergent (move towards each other), divergent (move away from each
other) and transform (move along side each other)
What is the concept of the Safety Factor in the context of slope stability? How does it relate to the
probability of failure of the slope?
- Safety factor is a measure of the stability of slope. It is the ration of the Maximum Resisting
Force (force acting to prevent slope movement) to the Driving Force (the force acting to
cause slope movement).
Explain the various terms in the Safety Factor equation.
- C= cohesion
- w= weight of potential failure block
- fish= angle of potential failure plain
- circle with line through it= angle of internal friction
Explain the importance water has in affecting the stability of slopes.
What are the hazards associated with stratovolcanoes?
- Pyroclastic flow
What is it about the nature of stratovolcanoes and their magma that leads to the dangers that you
- High viscosity, high water content
- Steep since “sticky” magma flows down sides
- Violent eruptions
Explain how ocean and continental crust is formed, indicating their genera