Seismicity of the United States 1975-1995. Seismicity refers to the geographic and historical distribution of earthquakes.
Images
Geologic Hazards Science Center images.
Filter Total Items: 286
Seismicity of the United States 1975-1995
Seismicity of the United States 1975-1995. Seismicity refers to the geographic and historical distribution of earthquakes.
ShakeMap Directivity Map
This ShakeMap of the January 17, 1994 M6.7 Northridge earthquake shaking shows the result of rupture directivity toward the north.
This ShakeMap of the January 17, 1994 M6.7 Northridge earthquake shaking shows the result of rupture directivity toward the north.
Active Emerson Fault
The Emerson fault, one of the segments that ruptured in the M7.2 1992 Landers, Calfornia earthquake.
The Emerson fault, one of the segments that ruptured in the M7.2 1992 Landers, Calfornia earthquake.
1992 M7.2 Landers, California Earthquake Slip Model
1992 M7.2 Landers, California Earthquake Slip Model1992 M7.2 Landers, California earthquake slip model
A slip model is a kinematic model that describes the amount, distribution, and timing of slip associated with an earthquake.
1992 M7.2 Landers, California Earthquake Slip Model
1992 M7.2 Landers, California Earthquake Slip Model1992 M7.2 Landers, California earthquake slip model
A slip model is a kinematic model that describes the amount, distribution, and timing of slip associated with an earthquake.
Cross-Sections of Seismicity Along the San Andreas Fault
Cross-Sections of Seismicity Along the San Andreas FaultCross-Sections of Seismicity Along the San Andreas Fault from "Lessons learned from the Loma Prieta, California, earthquake of October 17, 1989"
Cross-Sections of Seismicity Along the San Andreas Fault
Cross-Sections of Seismicity Along the San Andreas FaultCross-Sections of Seismicity Along the San Andreas Fault from "Lessons learned from the Loma Prieta, California, earthquake of October 17, 1989"
Segmentation of the San Andreas Fault
The segments of the San Andreas Fault, and the probability for strong shaking in the next 30 years on each segment.
The segments of the San Andreas Fault, and the probability for strong shaking in the next 30 years on each segment.
Catastrophic Landslide
The Mameyes, Puerto Rico, landslide, 1985. This landslide destroyed 120 houses and killed at least 129 people. The catastrophic slide was triggered by a tropical storm that produced extremely heavy rainfall.
The Mameyes, Puerto Rico, landslide, 1985. This landslide destroyed 120 houses and killed at least 129 people. The catastrophic slide was triggered by a tropical storm that produced extremely heavy rainfall.
Significant Landslide Events in the United States
The April 1983 landslide at Thistle, Utah, created a 200-ft-high (60-m-high) blockage of Spanish Fork canyon that caused disastrous flooding of the Thistle creek and Soldier Creek valleys upstream. The flooding caused by the landslide required relocation of a major highway and railway. An emergency spillway and diversion tunnels were constructed to drain
The April 1983 landslide at Thistle, Utah, created a 200-ft-high (60-m-high) blockage of Spanish Fork canyon that caused disastrous flooding of the Thistle creek and Soldier Creek valleys upstream. The flooding caused by the landslide required relocation of a major highway and railway. An emergency spillway and diversion tunnels were constructed to drain
Harmonic Tremor
During the first week of April a different type of seismic signature was showing up on seismograms from Mount St. Helens. On April 1 the first weak harmonic tremor was detected. Stronger bursts of harmonic tremor were recorded on the 2nd. The seismogram above is an example of harmonic tremor recorded at seismic station RAN on April 2.
During the first week of April a different type of seismic signature was showing up on seismograms from Mount St. Helens. On April 1 the first weak harmonic tremor was detected. Stronger bursts of harmonic tremor were recorded on the 2nd. The seismogram above is an example of harmonic tremor recorded at seismic station RAN on April 2.
Moment Tensor
The nine generalized couples of the seismic moment tensor. Modified after Aki and Richards (1980).
The nine generalized couples of the seismic moment tensor. Modified after Aki and Richards (1980).
Deformation Example - Deformed Rock
Photo of deformed rock. Deformation is a change in the original shape of a material. When we are talking about earthquakes, deformation is due to stress and strain.
Photo of deformed rock. Deformation is a change in the original shape of a material. When we are talking about earthquakes, deformation is due to stress and strain.
Richter Scale
The Richter magnitude scale was developed in 1935 by Charles F. Richter of the California Institute of Technology as a mathematical device to compare the size of earthquakes. The magnitude of an earthquake is determined from the logarithm of the amplitude of waves recorded by seismographs.
The Richter magnitude scale was developed in 1935 by Charles F. Richter of the California Institute of Technology as a mathematical device to compare the size of earthquakes. The magnitude of an earthquake is determined from the logarithm of the amplitude of waves recorded by seismographs.
1955 La Conchita Landslide
Photo of 1995 landslide in La Conchita, California. A landslide is a movement of surface material down a slope.
Photo of 1995 landslide in La Conchita, California. A landslide is a movement of surface material down a slope.