Industry-relevant training in Business, Technology, and Design to help professionals and graduates upskill for real-world careers.
Fun, engaging games to boost memory, math fluency, typing speed, and English skills—perfect for learners of all ages.
Enroll to start learning
You’ve not yet enrolled in this course. Please enroll for free to listen to audio lessons, classroom podcasts and take practice test.
Listen to a student-teacher conversation explaining the topic in a relatable way.
Signup and Enroll to the course for listening the Audio Lesson
Today, we're discussing tectonic earthquakes, which are the most common type. Can anyone tell me what causes them?
Is it because of the movement of Earth's plates?
Exactly! These earthquakes occur due to the movement of the lithospheric plates. Now, can anyone name the three types of plate boundaries?
Convergent, divergent, and transform!
Great! Let's remember that with the acronym 'CDT.' Now, which plate boundary do you think causes the largest earthquakes?
Convergent boundaries?
Correct! They produce significant stress that can lead to powerful earthquakes, like those in the Himalayas. To summarize: Tectonic earthquakes result from plate movements, particularly at convergent boundaries.
Signup and Enroll to the course for listening the Audio Lesson
Next, let's discuss volcanic earthquakes. What initiates these types of earthquakes?
Is it from magma movement beneath the Earth's surface?
Yes! The pressure from magma can fracture rocks and result in earthquakes. Can anyone think of a region known for volcanic earthquakes?
The Ring of Fire?
Exactly! That's a significant volcanic region. To help remember, think of volcanoes causing 'volcanic rumbles'. Summing up, volcanic earthquakes are caused by magma movement and are often precursors to eruptions.
Signup and Enroll to the course for listening the Audio Lesson
Let’s now look at collapse earthquakes. What causes these, and can someone give an example?
They occur when caves collapse, right? Like in limestone areas?
Exactly! And such earthquakes typically have low magnitudes but can impact infrastructure. Now, what about explosion-induced earthquakes?
Are those caused by nuclear tests or mining?
Correct! They have a distinct seismic signature. Let’s remember this with the phrase 'Man-Made Shakes.' In summary, collapse earthquakes are local phenomena, while explosion-induced earthquakes are results of human activities.
Signup and Enroll to the course for listening the Audio Lesson
Now, let’s explore reservoir-induced seismicity. Who can explain what causes these earthquakes?
They result from water filling in large reservoirs? The weight of the water changes the stress in the earth?
Exactly! This can trigger seismic activity along faults. An example is the Koyna Dam earthquake. What about isostatic adjustment earthquakes? Can anyone explain that?
They happen because of changes in weight on the crust, like glaciers melting?
Yes! As land adjusts, it can trigger earthquakes. Let’s summarize: Reservoir-induced earthquakes come from water pressure, while isostatic adjustments are due to changing surface loads.
Signup and Enroll to the course for listening the Audio Lesson
Lastly, we have induced seismicity. Who can give examples of human activities that lead to earthquakes?
Fracking and deep well injection?
Correct! These activities can alter the stress on faults, triggering earthquakes. Can you think of a location where this has been significant?
Oklahoma has had a lot of activity related to fracking.
Exactly! To remember, think 'Humans Shake too.' In summary, induced seismicity refers to earthquakes caused by our activities, affecting existing fault lines.
Read a summary of the section's main ideas. Choose from Basic, Medium, or Detailed.
This section categorizes earthquakes into various classes such as tectonic, volcanic, collapse, explosion-induced, reservoir-induced, and isostatic adjustment earthquakes, with a brief overview of each classification's characteristics.
Earthquakes are categorized according to their origin, which helps in understanding their mechanisms and implications for civil engineering and disaster preparedness. This section outlines the primary classifications:
Understanding the classification of earthquakes is crucial for civil engineers in designing resilient infrastructure and assessing seismic risks.
Dive deep into the subject with an immersive audiobook experience.
Signup and Enroll to the course for listening the Audio Book
Earthquakes are classified based on their origin or causative factors. These include:
This introductory statement explains that the focus of the section is on how earthquakes are categorized according to their causes. It indicates that various factors contribute to the occurrence of earthquakes, setting the stage for a detailed exploration of each type.
Think of classifying books in a library. Just as books can be sorted by genre, author, or publication date, earthquakes can be categorized based on their causes. This helps scientists understand and study them better.
Signup and Enroll to the course for listening the Audio Book
Tectonic earthquakes are caused by the movement of the Earth's lithospheric plates. These movements happen due to the Earth's internal heat and lead to stress build-up at the edges of these plates. When the stress exceeds the strength of the rocks, it results in an earthquake. Tectonic earthquakes are the most common type and can be very destructive.
Imagine two cars bumping against each other at a traffic light; the pressure builds as they push against one another until one moves. Similarly, tectonic plates push against each other, leading to seismic activity when stress is released.
Signup and Enroll to the course for listening the Audio Book
Volcanic earthquakes occur in areas with volcanic activity. They can result from the movement of magma beneath the Earth's surface, sudden fracturing of rocks due to pressure from magma, or the collapse of volcanic structures. While often localized, these events can indicate impending volcanic eruptions.
Think about how bubbles form in a boiling pot of water. When the pressure builds up from the heat, bubbles burst to the surface, similar to how volcanic activity can create tremors as magma moves and pressure builds.
Signup and Enroll to the course for listening the Audio Book
Collapse earthquakes are generally minor and occur when underground caves or mine tunnels collapse. They can also happen due to sudden failures of rock strata or roof falls in mines. Although these quakes usually have low magnitudes, they can still impact local structures and communities.
Picture a sandcastle that suddenly collapses when too much water erodes its base. Just as sand collapses, so too can underground structures lead to minor seismic events when they give way.
Signup and Enroll to the course for listening the Audio Book
These earthquakes are man-made and result from activities like nuclear detonations or large chemical explosions. Construction activities using heavy blasting can also induce such earthquakes. They typically last for a short duration and have a distinct seismic signature that differentiates them from natural earthquakes.
Think of throwing a rock into a pond. The ripples created are temporary and localized, similar to the way explosion-induced earthquakes behave — quick and distinct without causing widespread effects.
Signup and Enroll to the course for listening the Audio Book
These earthquakes occur when large reservoirs behind dams are filled. The added weight of the water increase stress on underlying faults and can lead to slippage. Changes in pore pressure from water infiltration can also reduce friction on faults, causing earthquakes.
Imagine sitting on a seesaw: if a friend jumps on one side suddenly, it can flip. Similarly, when water is added to a reservoir, it increases stress on fault lines, which can result in minor earthquakes.
Signup and Enroll to the course for listening the Audio Book
These earthquakes are connected to isostatic rebound, where land masses rise or fall due to the removal (like melting glaciers) or addition of surface loads (like sediment deposits). This adjustment of crustal weight can trigger seismic activity.
Think of a sponge that is compressed when squeezed; once you let go, it slowly expands back to its original shape. As the land adjusts to changes over time, it may also 'release' energy in the form of small earthquakes.
Signup and Enroll to the course for listening the Audio Book
This type of seismicity arises from activities such as deep well injection, hydraulic fracturing, mining, and geothermal extraction. These actions alter stress and pore pressure in the Earth's crust, potentially triggering earthquakes.
Picture a tightly packed crowd in a concert; when a few people push towards the exit, it can set off a chain reaction of movement in the crowd. Similarly, human interventions can disrupt stress balance in the Earth, leading to earthquakes.
Learn essential terms and foundational ideas that form the basis of the topic.
Key Concepts
Tectonic Earthquakes: Caused by plate movements.
Volcanic Earthquakes: Related to volcanic activity.
Collapse Earthquakes: Occur from underground structure failures.
Explosion-induced Earthquakes: Result from human-made detonations.
Reservoir-induced Seismicity: Due to stress from large reservoirs.
Isostatic Adjustment Earthquakes: Result from shifts in Earth's crust.
Induced Seismicity: Triggered by human activities.
See how the concepts apply in real-world scenarios to understand their practical implications.
The 1906 San Francisco Earthquake, a tectonic earthquake resulting from the movement along the San Andreas Fault.
Koyna Dam earthquake in India (1967) caused by reservoir-induced seismicity.
Use mnemonics, acronyms, or visual cues to help remember key information more easily.
When tectonic plates collide, earthquakes will reside.
Once upon a time, Earth's plates danced around, sometimes colliding, causing tremors that could be found, making local ground shake, with volcanic eruptions as well, to tell how Earth behaves, there's much more to tell.
Remember the acronym 'TVCEIR' to recall the earthquake types: Tectonic, Volcanic, Collapse, Explosion-induced, Reservoir-induced, and Induced seismicity.
Review key concepts with flashcards.
Review the Definitions for terms.
Term: Tectonic Earthquakes
Definition:
Earthquakes caused by the movement of Earth's tectonic plates.
Term: Volcanic Earthquakes
Definition:
Seismic events associated with volcanic activity.
Term: Collapse Earthquakes
Definition:
Minor earthquakes resulting from the collapse of underground structures.
Term: Explosioninduced Earthquakes
Definition:
Seismic events caused by human activities like nuclear detonations or mining blasts.
Term: Reservoirinduced Seismicity
Definition:
Earthquakes caused by the filling of large reservoirs affecting stress in the Earth.
Term: Isostatic Adjustment Earthquakes
Definition:
Seismic events resulting from the crust adjusting to changes in surface loads.
Term: Induced Seismicity
Definition:
Earthquakes triggered by human activities that alter natural stress on fault lines.