Local observations of the onset of a large earthquake: 28 June 1992 Landers, California
Richael Abercrombie, Jim Mori
1994, Bulletin of the Seismological Society of America (84) 725-734
The Landers earthquake (MW 7.3) of 28 June 1992 had a very emergent onset. The first large amplitude arrivals are delayed by about 3 sec with respect to the origin time, and are preceded by smaller-scale slip. Other large earthquakes have been observed to have similar emergent onsets, but the...
The co-seismic slip distribution of the Landers earthquake
J. Freymueller, N.E. King, P. Segall
1994, Bulletin of the Seismological Society of America (84) 646-659
We derived a model for the co-seismic slip distribution on the faults which ruptured during the Landers earthquake sequence of 28 June 1992. The model is based on the inversion of surface geodetic measurements, primarily vector displacements measured using the Global Positioning System (GPS). The inversion procedure assumes...
Shear zones formed along long, straight traces of fault zones during the 28 June 1992 Landers, California, earthquake
Arvid M. Johnson, Robert W. Fleming, Kenneth M. Cruikshank
1994, Bulletin of the Seismological Society of America (84) 499-510
Surface rupturing during the 28 June 1992 Landers, California, earthquake, east of Los Angeles, accommodated right-lateral offsets up to about 6 m along segments of distinct, en-echelon fault zones with a total length of 80 km. The offsets were accommodated generally not by faults—distinct slip surfaces—but rather by shear zones,...
Continuous borehole strain in the San Andreas fault zone before, during, and after the 28 June 1992, MW 7.3 Landers, California, earthquake
M.J.S. Johnston, A. T. Linde, D.C. Agnew
1994, Bulletin of the Seismological Society of America (84) 799-805
High-precision strain was observed with a borehole dilational strainmeter in the Devil's Punchbowl during the 11:58 UT 28 June 1992 MW 7.3 Landers earthquake and the large Big Bear aftershock (MW 6.3). The strainmeter is installed at a depth of 176 m in the fault zone approximately midway between...
Fault-zone waves observed at the southern Joshua Tree earthquake rupture zone
S. E. Hough, Y. Ben-Zion, P. Leary
1994, Bulletin of the Seismological Society of America (84) 761-767
Waveform and spectral characteristics of several aftershocks of the M 6.1 22 April 1992 Joshua Tree earthquake recorded at stations just north of the Indio Hills in the Coachella Valley can be interpreted in terms of waves propagating within narrow, low-velocity, high-attenuation, vertical zones. Evidence for our interpretation consists of:...
Southern surface rupture associated with the M 7.3 1992 Landers, California, earthquake
S. E. Hough
1994, Bulletin of the Seismological Society of America (84) 817-825
Although most evidence suggests that the 28 June 1992 M 7.3 Landers earthquake ruptured unilaterally north, significant surface rupture was mapped on the Eureka Peak and Burnt Mountain faults, to the south of the Landers epicenter. An eyewitness account reports that surface rupture occurred on the northern Eureka Peak fault...
Slip triggered on southern California faults by the 1992 Joshua Tree, Landers, and big bear earthquakes
Paul Bodin, Roger G. Bilham, Jeff Behr, Joan Gomberg, Kenneth W. Hudnut
1994, Bulletin of the Seismological Society of America (84) 806-816
Five out of six functioning creepmeters on southern California faults recorded slip triggered at the time of some or all of the three largest events of the 1992 Landers earthquake sequence. Digital creep data indicate that dextral slip was triggered within 1 min of each mainshock and that maximum slip...
Ammonium sorption to channel and riparian sediments: A transient storage pool for dissolved inorganic nitrogen
Frank J. Triska, Alan P. Jackman, John H. Duff, Ronald J. Avanzino
1994, Biogeochemistry (26) 67-83
Sediment (0.5 mm–2.0 mm grain size) was incubated in nylon bags (200 μm mesh) below the water table in the channel and in two transects of shallow wells perpendicular to the banks (to 18 m) of a third-order stream during August, 1987. One transect of wells drained steep old-growth forest,...
Magnetic field observations in the near-field the 28 June 1992 Mw 7.3 Landers, California, earthquake
M. J. Johnston, R.J. Mueller, Yoichi Sasai
1994, Bulletin of the Seismological Society of America (84) 792-798
Recent reports suggest that large magnetic field changes occur prior to, and during, large earthquakes. Two continuously operating proton magnetometers, LSBM and OCHM, at distances of 17.3 and 24.2 km, respectively, from the epicenter of the 28 June 1992 Mw 7.3 Landers earthquake, recorded data through the earthquake...
Pen rearing and imprinting of fall Chinook salmon
J.W. Beeman, J.F. Novotny
1994, Report
Results of rearing upriver bright fall chinook salmon juveniles in net pens and a barrier net enclosure in two backwater areas and a pond along the Columbia River were compared with traditional hatchery methods. Growth, smoltification, and general condition of pen-reared fish receiving supplemental feeding were better than those of...
Extremal bounds on earthquake movement from geodetic data: Application to the Landers earthquake
Hadley O. Johnson, Duncan Carr Agnew, Ken Hudnut
1994, Bulletin of the Seismological Society of America (84) 660-667
We present a technique to place quantifiable bounds on the moment of an earthquake from geodetic data, assuming known fault geometry. Application of this technique to the 1992 Landers earthquake shows that the moment must have been between 0.84 and 1.15 × 1020 Nm with 90% confidence (M 7.25 to...
Foreshocks, aftershocks, and earthquake probabilities: Accounting for the landers earthquake
Lucile M. Jones
1994, Bulletin of the Seismological Society of America (84) 892-899
The equation to determine the probability that an earthquake occurring near a major fault will be a foreshock to a mainshock on that fault is modified to include the case of aftershocks to a previous earthquake occurring near the fault. The addition of aftershocks to the background seismicity makes its...
Reconciling short recurrence intervals with minor deformation in the New Madrid seismic zone
E.S. Schweig, M.A. Ellis
1994, Science (264) 1308-1311
At least three great earthquakes occurred in the New Madrid seismic zone in 1811 and 1812. Estimates of present-day strain rates suggest that such events may have a repeat time of 1000 years or less. Paleoseismological data also indicate that earthquakes large enough to cause soil liquefaction have occurred several...
A salmon population model for evaluating alternative flow regimes
J. M. Bartholow, T. J. Waddle
1994, Book, Proceedings of the 21st Annual Water Resources Planning and Management Division Conference
No abstract available....
Water and wildlife enhancement with land retirement
E. Ekstrand, R. Johnson
1994, Book, Water policy and management: Solving the problems
No abstract available....
Technical understanding in successful environmental negotiations
N. Burkardt, B. L. Lamb, T. Waddle
1994, Book, Water Policy and Management: Solving the Problems
No abstract available....
Seismologists meet “Down Under”
William L. Ellsworth
1994, Eos Science News (75) 234-235
Planned presentations on hazard assessment and research weren't the only topics for discussion at the 27th General Assembly of the International Association of Seismology and Physics of the Earth's Interior (IASPEI), held from January 10–21 at the University of Victoria in Wellington, New Zealand.There was a more timely one unfolding:...
Earthquake refraction profiles of the root of the Sierra Nevada
Martha K. Savage, Li Li, Jerry P. Eaton, Craig H. Jones, James N. Brune
1994, Tectonics (13) 803-817
We examine the seismic structure of the Sierra Nevada using records of nine earthquakes and one explosion in and near the Sierra, recorded on stations in the Sierra. We first interpret travel times from these paths, which are confined to a single tectonic block, in terms of...
Cytonuclear genetics of experimental fish hybrid zones inside Biosphere 2
K.T. Scribner, John C. Avise
1994, PNAS (91) 5066-5069
Two species of mosquitofish (family Poeciliidae) known to hybridize in nature were introduced into freshwater habitats inside Biosphere 2, and their population genetics were monitored after 2 years. Within four to six generations, nuclear and cytoplasmic markers characteristic of Gambusia holbrooki had risen greatly in frequency, although some Gambusia affinis...
Galileo multispectral imaging of the north polar and eastern limb regions of the moon
M. J. S. Belton, R. Greeley, R. Greenberg, P. Geissler, A. McEwen, K.P. Klaasen, C. Heffernan, H. Breneman, T. V. Johnson, J. W. Head III, C. Pieters, G. Neukum, C. R. Chapman, C. Anger, M. H. Carr, M. E. Davies, F. P. Fanale, P.J. Gierasch, W.R. Thompson, J. Veverka, C. Sagan, A.P. Ingersoll, C.B. Pilcher
1994, Science (264) 1112-1115
Multispectral images obtained during the Galileo probe's second encounter with the moon reveal the compositional nature of the north polar regions and the northeastern limb. Mare deposits in these regions are found to be primarily low to medium titanium lavas and, as on the western limb, show only slight spectral...
Using regional seismic networks to study the Earth's deep interior
Harley M. Benz, J.E. Vidale, J. Mori
1994, Eos Science News (75) 225-229
Long-period or broadband data from global stations or small aperture arrays have traditionally been used to study the Earth's deep interior. However, recent seismic studies have shown that regional seismic networks can be an important tool in high- resolution studies of the upper mantle, coremantle boundary, and the inner and...
Compositions, growth mechanisms, and temporal relations of hydrothermal sulfide‐sulfate‐silica chimneys at the northern Cleft segment, Juan de Fuca Ridge
Randolph A. Koski, I. Jonasson, D. Kadko, Virginia K. Smith, Florence L. Wong
1994, Journal of Geophysical Research - Solid Earth (99) 4813-4832
Three active hydrothermal vents forming sulfide mounds and chimneys (Monolith, Fountain, and Pipe Organ) and more widely distributed inactive chimneys are spatially related to a system of discontinuous fissures and young sheet flow lavas at the northern Cleft segment, Juan de Fuca Ridge. The formation of zoned tubular Curich chimneys...
Comparison of 14C ages of hydrothermal petroleums
Bernd R. T. Simoneit, Keith A. Kvenvolden
1994, Organic Geochemistry (21) 525-529
In order to set limits on the time frame of formation of hydrothermal petroleum, we have obtained 14C ages on samples from three diverse regions; Gulf of California (Guaymas Basin), Northeast Pacific Ocean (Escanaba Trough and Middle Valley), and the East African Rift (Tanganyika Trough). The results date the source of...
Chemistry of dissolved organic matter in rivers, lakes, and reservoirs
J. A. Leenheer
1994, Book chapter, Environmental chemistry of lakes and reservoirs
Recent investigations provide new insight on the structural chemistry of dissolved organic matter (DOM) in freshwater environments and the role of these structures in contaminant binding. Molecular models of DOM derived from allochthonous and autochthonous sources show that short-chain, branched, and alicyclic structures are terminated by carboxyl or methyl groups...
Ecological mapping of whitebark pine in Glacier National Park
K. C. Kendall
1994, Book, Proceedings of a workshop on research and management in whitebark pine ecosystems
No abstract available....
