Podcast
Questions and Answers
What is geology?
What is geology?
Geology is the science that deals with the study of Earth's physical and chemical changes.
Which engineering discipline can benefit from geology in construction projects?
Which engineering discipline can benefit from geology in construction projects?
Geology helps to identify areas susceptible to failures due to geological hazards such as earthquakes, landslides, and ___________.
Geology helps to identify areas susceptible to failures due to geological hazards such as earthquakes, landslides, and ___________.
weathering effects
Match the branch of geology with its description:
Match the branch of geology with its description:
Signup and view all the answers
The mantle of the Earth is solid.
The mantle of the Earth is solid.
Signup and view all the answers
What is earthquake engineering?
What is earthquake engineering?
Signup and view all the answers
Earthquakes are the most catastrophic event that can occur on the planet's surface.
Earthquakes are the most catastrophic event that can occur on the planet's surface.
Signup and view all the answers
What are faults?
What are faults?
Signup and view all the answers
____ faults are cracks where one mass of rock slides downward and pulls away from another mass of rock.
____ faults are cracks where one mass of rock slides downward and pulls away from another mass of rock.
Signup and view all the answers
Match the seismic wave type with its description:
Match the seismic wave type with its description:
Signup and view all the answers
What is seismology?
What is seismology?
Signup and view all the answers
What is a seismologist?
What is a seismologist?
Signup and view all the answers
Earthquake focus refers to the point directly above the epicenter.
Earthquake focus refers to the point directly above the epicenter.
Signup and view all the answers
The oldest useful yardstick of the strength of an earthquake is the earthquake ________.
The oldest useful yardstick of the strength of an earthquake is the earthquake ________.
Signup and view all the answers
Match the following earthquake strength indicators with their descriptions:
Match the following earthquake strength indicators with their descriptions:
Signup and view all the answers
What are lifelines in the context of earthquakes?
What are lifelines in the context of earthquakes?
Signup and view all the answers
What is liquefaction?
What is liquefaction?
Signup and view all the answers
What are some types of landslides that can occur as a result of earthquakes?
What are some types of landslides that can occur as a result of earthquakes?
Signup and view all the answers
Study Notes
Geology
- Geology is the science that deals with the study of Earth's physical and chemical changes that occur on its surface and in its interior.
- It overlaps with other Earth sciences, including hydrology and atmospheric sciences.
- Geology plays a major role in different engineering disciplines, including Civil Engineering and Earthquake Engineering.
Importance of Geology in Construction
- Geology helps understand Earth's processes and is essential for understanding both natural and anthropogenic catastrophes.
- It provides knowledge about the site used in construction of buildings, dams, tunnels, and bridges.
- Geology helps identify areas susceptible to failures due to geological hazards such as earthquakes, landslides, and weathering effects.
Branches of Geology
- Physical Geology / Geomorphology: deals with the study of Earth's physical features, such as mountains, valleys, rivers, and lakes.
- Mineralogy: deals with the study of minerals.
- Petrology: deals with the study of rocks.
- Historical Geology: deals with the study of Earth's history and the changes that occurred in the past.
- Economic Geology: deals with the study of minerals and their economic importance.
Internal Structure of the Earth
- Crust: the uppermost solid shell of the Earth, making up less than 1% of its mass.
- Mantle: the zone within the Earth that lies between the core and the outermost layer, making up about 68% of the Earth's mass.
- Core: the very hot and dense center of the planet, making up about 31% of the Earth's mass.
Plate Tectonics
- The lithosphere is divided into several smaller parts called tectonic plates.
- These plates move and interact with each other, driven by convectional forces within the Earth.
- The movements and interactions of these plates produce earthquakes, volcanoes, mountain ranges, and other geological processes and features.
Plate Tectonic Boundary
- Three types of plate boundaries:
- Divergent boundary: where two tectonic plates are moving away from each other.
- Convergent boundary: where two tectonic plates are moving towards each other.
- Transform boundary: where two tectonic plates are moving past each other.
Earthquake Engineering
- Defined as the branch of engineering devoted to mitigating earthquake hazards.
- Scope: seismicity, nature, measures, and recording of earthquakes, planning for seismic risk assessment and mitigation, analysis, design, and construction of earthquake-resistant structures.
Earthquakes
- Motion or vibration of the Earth's surface that follows a release of energy in the Earth's crust.
- Can be generated by a sudden dislocation of segments of the crust, volcanic eruptions, or man-made explosions.
- Can trigger other natural hazards, such as slope failure, tsunamis, and floods.
Sources of Ground Movements
- Tectonic earthquakes
- Volcanoes
- Explosions
- Collapse of mines and large reservoirs
Earthquake: Fault Lines
-
Faults are cracks in the lithosphere caused by the stresses created as sections of a plate are moving in different directions.
-
Three types of faults:
- Normal fault: where one mass of rock slides downward and pulls away from another mass of rock.
- Reverse fault: where plates are being pushed together, involving upward movement as the plates collide and buckle upwards.
- Strike-slip fault: not mentioned in the text.### Earthquake Fault Lines
-
A strike-slip fault occurs when two plates slide past each other horizontally.
-
The San Andreas fault in California is a famous example of a strike-slip fault, causing many powerful earthquakes.
-
Other examples of strike-slip faults include the Anatolian Fault in Turkey and the Alpine Fault in New Zealand.
Earthquake Seismic Waves
- Earthquakes release energy as shock waves, known as seismic waves, which ripple across the Earth's surface.
- Seismic waves can travel up to 2 miles per second.
- There are two types of seismic waves: Body Waves (P and S waves) and Surface Waves (Love and Rayleigh Waves).
Seismology
- Seismology is the study of earthquakes and seismic waves that move through and around the Earth.
- A seismologist is a scientist who studies earthquakes and seismic waves.
Earthquake Focus and Epicenter
- The focus of an earthquake is where pressure builds along a fault line, causing it to fail deep underneath the Earth's crust.
- The point directly above the focus is termed the epicenter.
- Earthquake foci are confined to within a limited zone of the upper Earth, with a lower boundary at around 700 km depth from the surface.
Earthquake Strength: Intensity and Magnitude
- Earthquake intensity is a measure of the severity of an earthquake at a particular location, based on human reactions, observed damage, and physical effects.
- Intensity scales are subjective and dependent on construction practices and socio-economic conditions of a country.
- Magnitude is a quantitative measure of earthquake size that does not depend on population density or construction type.
Effects of Earthquakes
- Comprehensive regional earthquake impact assessments require an interdisciplinary framework that incorporates physical damage, social and economic consequences.
- Physical damage includes damage to buildings, lifelines, and critical facilities.
- Social and economic consequences include short- and long-term effects on communities and urban and industrial regions.
Damage to Buildings and Lifelines
- Extensive structural damage can occur to buildings, bridges, highways, and other lifelines during earthquakes.
- Lifelines include essential services such as electric power, gas, water, and wastewater systems, as well as transportation systems and infrastructure.
Effects on the Ground
- Ground effects are a significant contributor to damage of the built environment.
- Local geology and topography influence the travel path and amplification characteristics of seismic waves.
- Surface rupture can occur due to intense and long shaking, as well as fault ruptures, generating deep cracks and large gaps.
- Fault ruptures can cause large vertical movements of the ground, leading to severe damage to building foundations and underground networks.
- Liquefaction can occur due to excessive build-up of pore water pressure during earthquakes, leading to loss of stiffness and strength of soils.
- Landslides, including rockfalls, deep failure of slopes, and shallow debris flows, can be generated by the loss of shear strength in the soil.
Human and Financial Losses
- Over 1200 destructive earthquakes occurred worldwide in the 20th century, causing estimated damage of over $1 trillion.
- Annual losses average around $10 billion.
- Monetary losses due to collapsed buildings and lifeline damage are substantial.
- The cost of recovery and reconstruction is a severe consequence of earthquakes.
Studying That Suits You
Use AI to generate personalized quizzes and flashcards to suit your learning preferences.
Related Documents
Description
Learn about the importance of geology in civil engineering, including the study of Earth's physical and chemical changes on its surface.
