Strike-Slip Fault
... -Measures earthquake strength based on the amount of energy released. This amount is calculated by analyzing the physics of the earthquake. -The moment magnitude scale is preferred over the Richter scale by seismologists because it is more accurate. -In simple terms, this scale multiplies the area o ...
... -Measures earthquake strength based on the amount of energy released. This amount is calculated by analyzing the physics of the earthquake. -The moment magnitude scale is preferred over the Richter scale by seismologists because it is more accurate. -In simple terms, this scale multiplies the area o ...
GLOBAL HAZARD revision sheet 2 – how PLATE
... Draw a labelled diagram to show the features of these margins: Constructive ...
... Draw a labelled diagram to show the features of these margins: Constructive ...
Hazards Chapter 3
... levels of stress --- as long as stress forces do not exceed friction the rock mass will remain static --- where stress exceeds friction, slippage/movement occurs - The higher the stress level before friction fails, the greater and more violent will be the subsequent movement ...
... levels of stress --- as long as stress forces do not exceed friction the rock mass will remain static --- where stress exceeds friction, slippage/movement occurs - The higher the stress level before friction fails, the greater and more violent will be the subsequent movement ...
silent earthquakes and the popocatepetl volcano unrest
... monitoring of the volcano was carried out all along its last unrest period since 1994. Albeit the Popocatepetl activity was relatively lower during the time spans of the slow aseismic events (Figure 2), these observations are very limited for a definite correlation. Slow subduction transients of equ ...
... monitoring of the volcano was carried out all along its last unrest period since 1994. Albeit the Popocatepetl activity was relatively lower during the time spans of the slow aseismic events (Figure 2), these observations are very limited for a definite correlation. Slow subduction transients of equ ...
Click here for the "Dynamic Earth Vocabulary"
... The movements of particles of material as specific types of waves move through a specific material. Primary Wave: Known as a “p-wave”, is a type of seismic wave that causes particles in the ground to move in a push-pull motion similar to a coiled spring. Secondary Wave: Known as a “s-wave”, is a typ ...
... The movements of particles of material as specific types of waves move through a specific material. Primary Wave: Known as a “p-wave”, is a type of seismic wave that causes particles in the ground to move in a push-pull motion similar to a coiled spring. Secondary Wave: Known as a “s-wave”, is a typ ...
Homework Set 1
... (iv) At a depth of 10 km, what is the normal and shear stress acting on a fault that is oriented at an angle of 30 to 3? (read your answer directly off the graph using the angle 2) (4) (v) Would the fault in question (iv) be able to produce an earthquake? How can you tell? (2) (vi) At a depth o ...
... (iv) At a depth of 10 km, what is the normal and shear stress acting on a fault that is oriented at an angle of 30 to 3? (read your answer directly off the graph using the angle 2) (4) (v) Would the fault in question (iv) be able to produce an earthquake? How can you tell? (2) (vi) At a depth o ...
Earthquakes
... unit= 30 times more energy. 3) Moment magnitude (best estimate of energy) = (fault slip x fault area x strength of rock) ...
... unit= 30 times more energy. 3) Moment magnitude (best estimate of energy) = (fault slip x fault area x strength of rock) ...
1992 Cape Mendocino earthquakes
The 1992 Cape Mendocino earthquakes (or 1992 Petrolia earthquakes) occurred along the Lost Coast of Northern California on April 25 and 26. The three largest events were the M7.2 thrust mainshock that struck near the unincorporated community of Petrolia midday on April 25 and two primary strike-slip aftershocks measuring 6.5 and 6.6 that followed early the next morning. The sequence encompassed both interplate and intraplate activity that was associated with the Mendocino Triple Junction, a complex system of three major faults (including the Cascadia subduction zone, San Andreas Fault, and Mendocino Fracture Zone) that converge near Cape Mendocino. The total number of aftershocks that followed the events exceeded 2,000.The three shocks damaged and destroyed homes and businesses in Humboldt County and injured 356 people, but the single largest loss was due to a post-earthquake fire that consumed a business center in Scotia. Accelerometers that had been in place in the Cape Mendocino area since the late 1970s recorded the event and the readings were moderate to strong, with the exception of the instruments closest to the epicenter, which went off scale a few seconds into the recording. No surface ruptures were present in the epicentral area, but landslides closed roads and railroad tracks for at least a week while cleanup took place. Also discovered was about 1 m (3 ft 3 in) of coastal uplift near Cape Mendocino and Punta Gorda.As the largest earthquake in California since the 1989 Loma Prieta event several years earlier, the mainshock caused a non-destructive tsunami that quickly reached the coast, and eventually Alaska and Hawaii several hours later. The tsunami was significant not because of its run-up, but because of the speed with which it reached the coast and for how long the waves persisted. Other strong earthquakes have affected the same area, with some that were clearly associated with the (interplate) Mendocino Fracture Zone, and others (like the two shocks on April 26) were intraplate earthquakes that ruptured within the Gorda Plate, but events that are unequivocally associated with the Cascadia subduction zone are very infrequent.