Susan E. Hough
Susan Hough is a scientist in the Earthquake Hazards Program.
Science and Products
Filter Total Items: 127
The 1998 earthquake sequence south of Long Valley Caldera, California: Hints of magmatic involvement The 1998 earthquake sequence south of Long Valley Caldera, California: Hints of magmatic involvement
A significant episode of seismic and geodetic unrest took place at Long Valley Caldera, California, beginning in the summer of 1997. Activity through late May of 1998 was concentrated in and around the south moat and the south margin of the resurgent dome. The Sierran Nevada block (SNB) region to the south/southeast remained relatively quiet until a M 5.1 event occurred there on 9 June...
Authors
S. E. Hough, R.S. Dollar, P. Johnson
On the modified Mercalli intensities and magnitudes of the 1811-1812 New Madrid earthquakes On the modified Mercalli intensities and magnitudes of the 1811-1812 New Madrid earthquakes
We reexamine original felt reports from the 1811–1812 New Madrid earthquakes and determine revised isoseismal maps for the three principal mainshocks. In many cases we interpret lower values than those assigned by earlier studies. In some cases the revisions result from an interpretation of original felt reports with an appreciation for site response issues. Additionally, earlier studies...
Authors
S. E. Hough, J.G. Armbruster, L. Seeber, J.F. Hough
A volcano in North Carolina? A closer look at a tall tale A volcano in North Carolina? A closer look at a tall tale
The legacy of the 1811-1812 New Madrid, Central United States, earthquakes is one of tremendous enigma. We are left with just enough contemporary information to provide a measure of constraint on the isoseismal contours and therefore magnitudes of the three principal events (Nuttli, 1973; Street, 1982; Johnston, 1996; Hough et al., 2000), yet given the sparse population density and...
Authors
Susan Hough
On the modified Mercalli intensities and magnitudes of the 1811/1812 New Madrid, central United States, earthquakes On the modified Mercalli intensities and magnitudes of the 1811/1812 New Madrid, central United States, earthquakes
No abstract available.
Authors
S. E. Hough, J.G. Armbruster, Leonardo Seeber, J.F. Hough
Attenuation and source properties at the Coso Geothermal area, California Attenuation and source properties at the Coso Geothermal area, California
We use a multiple-empirical Green's function method to determine source properties of small (M −0.4 to 1.3) earthquakes and P- and S-wave attenuation at the Coso Geothermal Field, California. Source properties of a previously identified set of clustered events from the Coso geothermal region are first analyzed using an empirical Green's function (EGF) method. Stress-drop values of at...
Authors
S. E. Hough, J.M. Lees, F. Monastero
The Loma Prieta, California, earthquake of October 17, 1989: Aftershocks and postseismic effects The Loma Prieta, California, earthquake of October 17, 1989: Aftershocks and postseismic effects
While the damaging effects of the earthquake represent a significant social setback and economic loss, the geophysical effects have produced a wealth of data that have provided important insights into the structure and mechanics of the San Andreas Fault system. Generally, the period after a large earthquake is vitally important to monitor. During this part of the seismic cycle, the...
Authors
Paul Reasenberg, Lynn Dietz, William Ellsworth, Robert Simpson, John Gephart, Susan Schwartz, Glenn Nelson, H. Guo, A. Lerner-Lam, William Menke, Susan Hough, Leif Wennerberg, K.S. Breckenridge, Jeff Behr, Roger Bilham, Paul Bodin, Arthur Sylvester, Jon Galehouse, R. Burgmann, Paul Segall, Michael Lisowski, Jerry Svarc, John Langbein, Mark Linker, J.R. Rice, M. Gladwin, R. Gwyther, R.H.G. Hart, Randall Mackie, Theodore Madden, Edward Nichols
The variability of PSV response spectra across a dense array deployed during the Northridge aftershock sequence The variability of PSV response spectra across a dense array deployed during the Northridge aftershock sequence
This study addresses the variability of pseudo-velocity response spectra across an array deployed on stiff soil in the San Fernando Valley during the Northridge (Mw 6.7) aftershock sequence. The separation between stations ranged from 0.5 to 5 km, and the aftershock magnitudes ranged from 2.3 to 4.0. We find that 95-percent of observed response spectra are within a factor of 1.9 to 2.6...
Authors
Edward Field, Susan Hough
Aftershocks: Are they earthquakes or afterthoughts? Aftershocks: Are they earthquakes or afterthoughts?
We tend to view aftershocks as after-thoughts in their scientific as well as societal importance. The media often ask seismologists: “Was it just an aftershock?” with the “just” implying that aftershocks present little cause for concern. Seismologists themselves tend to dismiss the importance of events that follow a large mainshock. Even appreciable aftershocks typically generate only a...
Authors
S. E. Hough, L.M. Jones
Empirical Green's function analysis: Taking the next step Empirical Green's function analysis: Taking the next step
An extension of the empirical Green's function (EGF) method is presented that involves determination of source parameters using standard EGF deconvolution, followed by inversion for a common attenuation parameter for a set of colocated events. Recordings of three or more colocated events can thus be used to constrain a single path attenuation estimate. I apply this method to recordings...
Authors
S. E. Hough
Observational constraints on earthquake source scaling: Understanding the limits in resolution Observational constraints on earthquake source scaling: Understanding the limits in resolution
I examine the resolution of the type of stress drop estimates that have been used to place observational constraints on the scaling of earthquake source processes. I first show that apparent stress and Brune stress drop are equivalent to within a constant given any source spectral decay between ω1.5 and ω3 (i.e., any plausible value) and so consistent scaling is expected for the two...
Authors
S. E. Hough
On the coherence of ground motion in the San Fernando valley On the coherence of ground motion in the San Fernando valley
We present an analysis of the coherence of seismic ground motion recorded on alluvial sediments in the San Fernando Valley, California. Using aftershocks of the 17 January 1994 Mw6.7 earthquake recorded at a quasi-dense array of portable stations, we analyze the coherence of three well-recorded magnitude 3.7 to 4.0 events over the frequency range 0.5 to 15 Hz and a distance range of 0.5...
Authors
S. E. Hough, E. Field
Earthquakes in the Los Angeles metropolitan region: A possible fractal distribution of rupture size Earthquakes in the Los Angeles metropolitan region: A possible fractal distribution of rupture size
Although there is debate on the maximum size of earthquake that is possible on any of several known fault systems in the greater Los Angeles metropolitan region, it is reasonable to assume that the distribution of earthquakes will follow a fractal distribution of rupture areas. For this assumption and an overall slip-rate for the region of approximately 1 centimeter per year, roughly one...
Authors
S. E. Hough
Science and Products
Filter Total Items: 127
The 1998 earthquake sequence south of Long Valley Caldera, California: Hints of magmatic involvement The 1998 earthquake sequence south of Long Valley Caldera, California: Hints of magmatic involvement
A significant episode of seismic and geodetic unrest took place at Long Valley Caldera, California, beginning in the summer of 1997. Activity through late May of 1998 was concentrated in and around the south moat and the south margin of the resurgent dome. The Sierran Nevada block (SNB) region to the south/southeast remained relatively quiet until a M 5.1 event occurred there on 9 June...
Authors
S. E. Hough, R.S. Dollar, P. Johnson
On the modified Mercalli intensities and magnitudes of the 1811-1812 New Madrid earthquakes On the modified Mercalli intensities and magnitudes of the 1811-1812 New Madrid earthquakes
We reexamine original felt reports from the 1811–1812 New Madrid earthquakes and determine revised isoseismal maps for the three principal mainshocks. In many cases we interpret lower values than those assigned by earlier studies. In some cases the revisions result from an interpretation of original felt reports with an appreciation for site response issues. Additionally, earlier studies...
Authors
S. E. Hough, J.G. Armbruster, L. Seeber, J.F. Hough
A volcano in North Carolina? A closer look at a tall tale A volcano in North Carolina? A closer look at a tall tale
The legacy of the 1811-1812 New Madrid, Central United States, earthquakes is one of tremendous enigma. We are left with just enough contemporary information to provide a measure of constraint on the isoseismal contours and therefore magnitudes of the three principal events (Nuttli, 1973; Street, 1982; Johnston, 1996; Hough et al., 2000), yet given the sparse population density and...
Authors
Susan Hough
On the modified Mercalli intensities and magnitudes of the 1811/1812 New Madrid, central United States, earthquakes On the modified Mercalli intensities and magnitudes of the 1811/1812 New Madrid, central United States, earthquakes
No abstract available.
Authors
S. E. Hough, J.G. Armbruster, Leonardo Seeber, J.F. Hough
Attenuation and source properties at the Coso Geothermal area, California Attenuation and source properties at the Coso Geothermal area, California
We use a multiple-empirical Green's function method to determine source properties of small (M −0.4 to 1.3) earthquakes and P- and S-wave attenuation at the Coso Geothermal Field, California. Source properties of a previously identified set of clustered events from the Coso geothermal region are first analyzed using an empirical Green's function (EGF) method. Stress-drop values of at...
Authors
S. E. Hough, J.M. Lees, F. Monastero
The Loma Prieta, California, earthquake of October 17, 1989: Aftershocks and postseismic effects The Loma Prieta, California, earthquake of October 17, 1989: Aftershocks and postseismic effects
While the damaging effects of the earthquake represent a significant social setback and economic loss, the geophysical effects have produced a wealth of data that have provided important insights into the structure and mechanics of the San Andreas Fault system. Generally, the period after a large earthquake is vitally important to monitor. During this part of the seismic cycle, the...
Authors
Paul Reasenberg, Lynn Dietz, William Ellsworth, Robert Simpson, John Gephart, Susan Schwartz, Glenn Nelson, H. Guo, A. Lerner-Lam, William Menke, Susan Hough, Leif Wennerberg, K.S. Breckenridge, Jeff Behr, Roger Bilham, Paul Bodin, Arthur Sylvester, Jon Galehouse, R. Burgmann, Paul Segall, Michael Lisowski, Jerry Svarc, John Langbein, Mark Linker, J.R. Rice, M. Gladwin, R. Gwyther, R.H.G. Hart, Randall Mackie, Theodore Madden, Edward Nichols
The variability of PSV response spectra across a dense array deployed during the Northridge aftershock sequence The variability of PSV response spectra across a dense array deployed during the Northridge aftershock sequence
This study addresses the variability of pseudo-velocity response spectra across an array deployed on stiff soil in the San Fernando Valley during the Northridge (Mw 6.7) aftershock sequence. The separation between stations ranged from 0.5 to 5 km, and the aftershock magnitudes ranged from 2.3 to 4.0. We find that 95-percent of observed response spectra are within a factor of 1.9 to 2.6...
Authors
Edward Field, Susan Hough
Aftershocks: Are they earthquakes or afterthoughts? Aftershocks: Are they earthquakes or afterthoughts?
We tend to view aftershocks as after-thoughts in their scientific as well as societal importance. The media often ask seismologists: “Was it just an aftershock?” with the “just” implying that aftershocks present little cause for concern. Seismologists themselves tend to dismiss the importance of events that follow a large mainshock. Even appreciable aftershocks typically generate only a...
Authors
S. E. Hough, L.M. Jones
Empirical Green's function analysis: Taking the next step Empirical Green's function analysis: Taking the next step
An extension of the empirical Green's function (EGF) method is presented that involves determination of source parameters using standard EGF deconvolution, followed by inversion for a common attenuation parameter for a set of colocated events. Recordings of three or more colocated events can thus be used to constrain a single path attenuation estimate. I apply this method to recordings...
Authors
S. E. Hough
Observational constraints on earthquake source scaling: Understanding the limits in resolution Observational constraints on earthquake source scaling: Understanding the limits in resolution
I examine the resolution of the type of stress drop estimates that have been used to place observational constraints on the scaling of earthquake source processes. I first show that apparent stress and Brune stress drop are equivalent to within a constant given any source spectral decay between ω1.5 and ω3 (i.e., any plausible value) and so consistent scaling is expected for the two...
Authors
S. E. Hough
On the coherence of ground motion in the San Fernando valley On the coherence of ground motion in the San Fernando valley
We present an analysis of the coherence of seismic ground motion recorded on alluvial sediments in the San Fernando Valley, California. Using aftershocks of the 17 January 1994 Mw6.7 earthquake recorded at a quasi-dense array of portable stations, we analyze the coherence of three well-recorded magnitude 3.7 to 4.0 events over the frequency range 0.5 to 15 Hz and a distance range of 0.5...
Authors
S. E. Hough, E. Field
Earthquakes in the Los Angeles metropolitan region: A possible fractal distribution of rupture size Earthquakes in the Los Angeles metropolitan region: A possible fractal distribution of rupture size
Although there is debate on the maximum size of earthquake that is possible on any of several known fault systems in the greater Los Angeles metropolitan region, it is reasonable to assume that the distribution of earthquakes will follow a fractal distribution of rupture areas. For this assumption and an overall slip-rate for the region of approximately 1 centimeter per year, roughly one...
Authors
S. E. Hough