Spahr
C. Webb
Jerome
M. Paros/Lamont Research 
Professor
of Observational Physics
Adjunct
Professor, Department
of Earth and Environmental Sciences
Lamont
Doherty Earth Observatory
[Research
Projects]
[CV] [contact]
[gizmos]
Spahr
Webb holds the Jerome M. Paros/Lamont Research professorship in Observational
Sciences at the Lamont Doherty Earth Observatory which
Is part of Columbia University’s new Climate School.
He is also an Adjunct Professor within the Department of Earth and
Environmental Sciences Department of the Columbia University. His group develops instrumentation to better
observe geophysical and oceanographic processes. A principle focus now is on
subduction zones and the hazards of megathrust earthquakes with an emphasis on
observing slow slip events (SSEs or slow earthquakes). The distribution of slip
in SSEs should inform
on the coupling behavior of megathrust faults and which have preceded several
recent giant earthquakes, and thus may provide the potential for early warning.
Other efforts include measuring deformation near the trench of subduction zones
using GPS-acoustic techniques, monitoring magma chamber processes beneath Axial
volcano using the compliance method. His
group runs a fleet of ocean bottom seismometers that have been extensively
deployed for studies of the oceanic crust and upper mantle.
Spahr
Webb hold B.S. degrees in Physics and also Earth and Planetary Sciences from
MIT and a PhD in oceanography from the Scripps Institution of Oceanography.
845-365-8439
scw@ldeo.columbia.edu
107 Seismology
Lamont Doherty Earth
Observatory
61 Route 9W
Palisades, NY 10964
Current
Research Projects
New
Project (Nov. 2021):
“Optimal
integration of seafloor pressure and oceanographic data for vertical marine
geodesy at subduction zones “
Collaborative
project with Randall Watt and Matt Wei (URI), with international collaborators
Laura Wallace (GNS, New Zealand), Yoshi Ito (U. Kyoto, Japan) and Kimihiro Mochizuki
(Earthquake Research Institute, Univ. of Tokyo, Japan).
The
largest and most dangerous earthquakes are subduction zone earthquakes where
the source of the earthquake is almost completely underwater. The size of an
earthquake and the propensity of an earthquake to create large dangerous
tsunamis is determined by variations in the plate interface coupling which
creates locked and unlocked regions of the fault. Understanding these variations
in plate coupling is critical to understanding these dangerous earthquakes.
Strain is released along some offshore parts of fault interfaces in occasional
slow slip events (SSEs) where the fault moves much as with a normal earthquake,
but the stored energy is released so slowly that these events are barely or not
detectable on land. Regions between the
SSE regions may remain locked, producing the potential for large tsunamigenic
earthquakes. There is some evidence that SSEs on one part of a plate interface
may increase strain on adjacent parts, triggering large earthquakes. Seafloor
pressure gauges can detect SSEs as the seafloor moves upward during a SSE, decreasing the depth of the gauge. A
SSE was detected and mapped in our proposed study region offshore New Zealand
in 2015 using pressure gauges, as this is the only currently feasible method
appropriate for wide application offshore.
Those observations were greatly limited by the effects of oceanographic
noise from ocean eddies. A much larger experiment is now planned for the same
region. By adding oceanographic observations of near-seafloor current and
vertical echo sounder data, the research should show this noise source can be
much reduced and therefore reveal the spatial and temporal extent of offshore
SSEs in greater detail and with better accuracy, improving our understanding of
plate coupling relevant to understanding great earthquakes.
During
this large collaborative experiment with New Zealand and Japanese scientists, a
large array of ocean bottom geodetic, oceanographic, and seismological
instruments will be deployed for two years offshore of the east coast of New
Zealand's North Island, where one or more shallow SSEs are expected to occur
during the deployment. The joint array
would include 44 seafloor absolute pressure gauges (APGs) and 12 current meters
and upward looking sonars to test and develop innovative methods to remove
contaminating pressure variations that arise within the water column (labeled
oceanographic noise). The reduced-noise seafloor data will enable more accurate
description of the spatio-temporal evolution of offshore SSEs. For the first
time, an array of 11 APG sensors equipped with a system for removing long term
drift from sensor data will be deployed, with potential long term benefit for
oceanographic observations and for applying seafloor vertical geodesy at
tectonic strain rates. Data from 21 ocean bottom seismometers in the combined
array will be used to probe the relationship between earthquakes and tremor and
seafloor SSEs. These observations will advance our understanding of offshore
variations in plate coupling in subduction zones.
We
plan to deploy the instruments in late Fall 2022 and recover the instruments in
late Fall 2024. A large subset of the
instruments which do not have two year recording
capacities will be recovered, the data downloaded, and returned to the seafloor
in late Fall 2023. I am looking for a graduate student to work with me on this
research project.
Ongoing
Research Project:
“Three
Compliance Instruments for Axial Volcano to Observe Long Term Evolution of the
Magma Chamber and in Support of OOI Observation”
Despite decades of observations, how magma migrates
and is stored within volcanoes remains poorly understood because there are few
means to continuously monitor changes within magma chambers beneath volcanoes.
Such measurements are needed to understand when and how the gradual emplacement
of magma finally triggers an eruption.
The instrumentation developed will provide the potential to monitor
changes in the magma content continuously beneath undersea volcanoes and thereby
provide a better understanding of volcano processes that can also be applied to
volcanos on land that pose a major hazard to millions of people.
Axial Volcano, a large, very active undersea volcano
offshore the US West Coast is currently monitored using sensors that transmit
data through the NSF supported Ocean Observatories Initiative cable to
shore. Sensors on these cables measured
changes in the compliance of seafloor preceding and following an eruption in
2015 associated with changes in the magma chamber, but the noise level of these
sensors limited the sensitivity of the observations and the observation period
to the winter months when the compliance signal was larger. New compliance
sensors with better sensitivity and a lower noise level will be constructed
using more optimal sensors and placed beneath on the seafloor beneath large
shields that protect the sensors from noise from ocean currents. Compliance, a
measure the deformation of the seafloor under the loading of long period ocean
waves, depends on the elastic properties of the underlying Earth and thereby to
the fraction of magma within the magma chamber. The current shielding developed
will also have applicability for reducing the noise levels for the horizontal
components of broadband seismometers installed on the seafloor. Ocean bottom
seismometers are critical to understanding many Earth processes, but the high
noise levels due to ocean floor currents limits the types and quality of
observations that can be made.
The three instruments were deployed and recovered in
August 2021 using the ROV Jason. We are
conducting a final set of test deployments of the instruments in June, 2022
also using the ROV Jason. We plan to make compliance measurements at about six
sites on the seafloor above the magma chamber of Axial Volcano. Future plans
are to make two year long deployments of these
instruments to track changes in the magma chamber preceding and hopefully
during and following the next eruption of Axial Volcano.
Ongoing Research Project:
“Measuring
strain along the Aleutian subduction zone trench to better constrain seismic
and tsunami hazard”
Collaborative
project with Scott Nooner (UNCW) and David Chadwell (SIO)
We are entering the last year of a five year long project to GPS-acoustic methods to measure
precise locations (<1cm error) with the global GNSS reference frame of the
centers of acoustic arrays transponder established on the seafloor at three
locations about 70km from the trench along the Alaskan subduction zone bridging
the “Shumagin Seismic Gap”. The original plan was to measure strain along this
segment of the subduction zone in a region where coupling between the down
going plate and the North American plate appeared to transition from strongly
coupled to the east of the Shumagin islands to apparently coupled in the
Shumagin island region. With the occurrence three very large earthquakes in
this former “seismic gap” in 2021 and 2022, are focus is now measuring the near
trench displacement associated with these three large earthquakes. Several
talks will be presented with preliminary results at the Fall 2021 AGU meeting.
Ongoing Research Project:
“Validating
Pressure Gauges for Seafloor Seismology and Geodesy”
There are two components of this research project.
The first is to examine the results from seafloor deployments of new Pressure
Ocean Bottom Seismometer (POBS) instruments equipped with a system called
“A-0-A” to remove drift from the absolute pressure gauges. Our observations
suggest corrected drifts of less than 1 cm for data from seafloor absolute
pressure gauges deployed for one year offshore of New Zealand. A paper
describing these results has recently been submitted. The other component of this research project
to measure relative calibrations as a function of pressure for the responses
the three pressure sensors currently commonly used for seismic observations
within the world’s ocean bottom seismometer fleets: 1) the differential pressure gauge or DPG, 2)
the absolute pressure gauge or APG and 3) standard hydrophones.
Gizmos:
The group has been developing seafloor
instrumentation for decades. Important early developments include the
differential pressure gauge (DPG), an early instrument for seafloor electromagnetic
studies (EM), and one of the first broad band OBSs.
This instrument enabled important experiments such as the MELT experiment, two
Lau Basin tomography deployments, the GLIMPSE deployment and many others. More
recent developments include a new high resolution, high sampling absolute
pressure gauge (APG), which has been incorporated in the new POBSs
instrument for both seismic and pressure observations.
The trawl resistant mount (TRM) shielded OBS enabled
the first shallow water deployments in Cascadia and demonstrated the value of
large heavy shields for reducing the noise from seafloor currents. The
shielding coupled with methods to reduce tilt and compliance noise enabled some
of first observations of receiver functions from the shallow seafloor.
Trawl Resistant Mount (TRM) OBS showing underside
with sensor hanging from shield
during instrument recovery.
One of the new Pressure OBS features a system for
removing drift from absolute pressure gauge
seafloor data called “A-0-A” being worked on in the
lab of R/V Tangaroa
One of the new seafloor compliance instruments with
and without its cover designed to reduce
long period noise from seafloor current.
SPAHR
C. WEBB
Lamont-Doherty Earth Observatory,
Columbia University, Palisades, N.Y. 10964
Tel: 914-365-8439, Fax: 914-365-8150
email: scw@ldeo.columbia.edu
Profession Preparation:
B.S. 1978, Massachusetts
Institute of Technology, Physics, and Earth and Planetary
Science
Ph.D. 1984, University of California, San Diego,
Oceanography
Professional Appointments:
2008-Present Jerome
Paros Senior Research Scientist, Lamont-Doherty Earth Observatory, Columbia
University, Palisades, N.Y.
2000-2008 Langseth-PGI
Senior Research Scientist, Lamont-Doherty Earth Observatory, Columbia
University, Palisades, N.Y.
2000-Present Adjunct Professor, Department of
Earth and Environmental Science,
Columbia
University
1997-2002 Research
Oceanographer, Scripps Institution of Oceanography, University of California,
San Diego, La Jolla, CA. (on leave 2000-2002)
1993-1997 Associate Research Oceanographer, Scripps
Institution of
Oceanography, University of California, San
Diego, La Jolla, CA
1986-1993 Assistant Research Oceanographer, Scripps
Institution of
Oceanography, University of California, San
Diego, La Jolla, CA.
1984-1986 Postdoctoral Scholar, Woods Hole
Oceanographic Institution,
Woods Hole, MA.
Research Activities:
Broad
band marine seismology, structure of oceanic mantle and crust.
Marine
geodesy focused on long term hazard of subduction zones, and detection of slow
slip events
and
volcanic eruptions.
Structure
and seismicity of subduction zones, ridge crests and seafloor hydrothermal
systems.
Propagation
and sources of microseisms, infragravity waves and the “hum of the Earth”.
Marine
instrumentation for geophysical, geodetic and oceanographic applications.
Professional Societies:
American
Geophysical Union, Seismological Society of America.
Graduate Students Supervised (SIO):
Mark
A. Mc Donald, Ph.D 1994
Wayne
C.Crawford, Ph.D 1994
Robert
A. Sohn, Ph.D 1996
Robert
Prescott
Charles
Golden PhD.
2000.
Graduate Students Supervised (LDEO):
R.
Chadwick Holmes, PhD 2009
Yang
Zha, PhD 2015
PhD Defense Committees
Sarah
Little (WHOI, 1986)
Milton
Garces (SIO, 1996)
Graham
Cairns (U. Toronto, 1998)
Nancy
Kanjorski (SIO)
Nick
Harmon (Brown, 2006)
Ran
Qin (2008)
Milena
Marjanovic (2013)
Anna
Foster (2014)
Jiyao
Li (2016)
Kira
Olsen (2019)
Josh
Russel, (2020)
Christine
Chesley (2021)
Habilitation à diriger des recherches (HDR) defense
for Wayne Crawford, Paris, France, 2014.
Postdoctoral Associates:
Vallerie
Ballu , 1994
Wayne
Crawford, 1994-1995
Scott
Nooner 2006-2008
Recent Classroom Teaching
Quantitative
Methods on Data Analysis, Fall 2002, 2004, 2006
Senior
Thesis Seminar Fall 2010, 2011, 2012, 2014, Spring 2011, 2012, 2015, 2021
Seismology
Group Seminar 2010-2021
Chair,
OBSIP management committee 2002 (member 2000- 2005).
Chair,
Interridge Underwater
Technology Working Group 2002
Co-Chair,
2003 Ocean Bottom Seismometers (OBS), Technology and Opportunities Meeting,
Taipei
Ridge2000
Steering Committee (2008-2011)
Workshop
for Developing a Broadband Ocean Bottom Seismometer Pool in the UK, Southampton
(2009)
LDEO search Committees, various
LDEO
Graduate admissions committee (2001-2006, 2008, 2009, 2010, 2013, 2015)
LDEO
Post Doc committee (2001-2004)
LDEO
PGI Junior Chair committee (2015)
LDEO
OTIC committee co-chair, (2011-2017)
LDEO
Promotions and Careers Committee (2017-2020)
Recent Research Cruises:
February 2000. (ship: Melville), San Diego to Manzanillo, active source
electromagnetic sounding (MOSES) using deployed magnetometer array (20 OBM) and
vertical electrical dipole. Extensive compliance measurements between 9-03,
9-50N, EPR (EM w/Evans, Compliance w/Crawford).
February 2000,
(ship: Ewing), Littleton-Suva, recovery of Woodlark OBS array.
May 2001, (ship:
Endeavor), Narragansett, testing of AUVOBS (APOGEE) prototype, w/ Sohn.
July 2001, (ship,
Weatherbird), Bermuda, testing of AUVOBS (APOGEE) prototype, w/ Sohn.
Nov.- Dec. 2001,
(ship: Melville), Papeete-Easter, deploy 28 OBS, seismic refraction, gravity,
seabeam, dredging, gross grain ridge expedition (w/Forsyth).
Oct.- Nov.- 2002, (ship:
Melville), Arica-Valrpraison, recover OBS,
gravity, seabeam, dredging, GLIMPSE expedition (w/Forsyth).
May 2003 (ship:Ewing) Gulfport. Ewing source level measurements.
Sept. 2003 (ship:
Weatherbird) Bermuda Compliance meter tests.
Nov.. 2005
(ship Sproul) San Diego, compliance meter, buried sensor tests
Dec. 2005 (ship
Oceanus) Woods Hole, buried sensor tests
June 2003: (ship:
Kaiyo): Tokyo-Saipan 50 OBS deployment for Wiens in Marianas.
Nov. 2003: (ship:
Ewing): San Juan-Bermuda, active source OBS for Sohn, also test compliance
sensors.
May2004: (ship:
Wecoma) Saipan-Guam, OBS recovery leg for Marianas
October 2004
(ship: Universtatis) Milazzo, Sicily, OBS deployment Calabria
January 2005
(ship Hesperides) Ushauia, Arg. Punta
Arenas Chile, Deception Island OBS
February 2005
(ship: Las Palmas) Ushuai, OBS recovery
August 2005,
(ship: Universtatis) Milazzo, Sicily, OBS recovery Calabria
Nov. 2005 (ship
Sproul) San Diego, compliance meter, buried sensor tests
Dec. 2005 (ship Oceanus) Woods Hole, buried sensor
tests
Sept. 2006 (ship:Sproul) San Diego, compliance meter and bottom pressure
recorder tests
Nov. 2006 (ship:Sproul) San Diego, compliance meter and bottom pressure
recorder tests
Feb.-Mar. 2007
(ship: Atlantis) Manzanillo, compliance study of EPR ridge crest from 9 to 10
N, and deployment of 19 bottom pressure recorders
May, 2007 (ship:
Seward Johnson), Granada, deployment of a radio- telemetered ocean shelf ocean
bottom seisometer system
(with WHOI collaborators).
Dec. 2007, (ship-
R/V Langseth) airgun source level measurements
Jan. 2008, (ship-
R/V Langseth) airgun source level measurements.
June 2008 (ship:
Atlantis) Manzanillo- San Diego, Alvin geodetic benchmark observations, w/Nooner.
Sept. 2008, 2009
(ship; Seawolf), New York, tests of SOBs (shielded OBS), w/Barclay.
Nov. 2009 (ship:
Revelle) Nuku'alofa, Tonga- Suva, Fiji, OBS deployment for Lau basin OBS
experiment (w/Wiens).
Dec. 2009 (ship:
Atlantis) Manzanillo- Puerto Caldera (CR), Alvin geodetic benchmark
observations, BPR recoveries, w/Nooner.
June 2010 (ship;
Seawolf), Stonybrook, tests of SOBs (shielded OBS), w/Barclay.
Nov. 2010 (ship:
Kilo Moana) Suva, Fiji - Nuku'alofa, Tonga-, OBS recovery for Lau basin OBS
experiment (w/Wiens).
June-August 2011
(ship: R/V Langseth) Kodiak-Dutch Harbor, MCS, Active Source OBS study of
Aleutian subduction zone, w/ Shillington.
October, 2011
(ship: Atlantis), San Diego- Balboa Panama, Geodetic work, mapping with S.
Nooner, R. Buck, V. Ferrini.
March, 2014,
(ship R/V Connecticut) testing of BPR and OBS instrumentation.
May, 2014, (ship
R/V Tangaroa), Wellington, N.Z., OBS/BPR array to study slow slip events (SSE)
on the Hikurangi subduction zone, w L. Wallace (lead), A. Sheehan, S. Schwartz
(and Japanese collaborators).
June, 2014 (ship
R/V Thompson), Newport, OR. Development of seafloor geodetic GPS- acoustic
(GPSA) benchmarks for use with ROVs, w/ C.D. Chadwell (lead) and S.L Nooner
June, 2015, (ship
R/V Revelle), Wellington, N.Z., OBS/BPR array to study slow slip events (SSE)
on the Hikurangi subduction zone, w L. Wallace (lead), A. Sheehan, S. Schwartz
(and Japanese collaborators).
August, 2015,
(ship R/V Connecticut) testing of BPR and OBS instrumentation.
April 24-26, 2017
(ship R/V Connecticut) deployment of OBS with pressure gradient sensors, Groton
CT.
Aug. 2017 (ship
R/V Connecticut) recovery of OBS with pressure gradient sensors, Groton CT.
May 9-29, 2018
(ship R/V Sikuliaq) Seward, Alaskan Amphibious Seismic Community Experiment
(AASCE)-45 OBS deployed,
3 GPSA sites established, and 2 new POBS deployed
August 23-24 and
Sept. 5-6 (ship R/V Connecticut) Deploy, recover shielded OBS with horizontal
pressure gauges. Also deploy, recover two POBSs.
Oct 1-19, 2018
(ship R/V Tangaroa), Wellington NZ. deploy Absolute pressure gauges, three
POBSs strong motion/pressure instruments and two GPSA sites offshore of Hawkes
Bay, New Zealand studying slow slip events.
Aug. 9-29, 2019
(ship R/V Sikuliaq w/Jason) Seward to Kodiak, Alaskan Amphibious Seismic
Community Experiment (AASCE)- recovery of OBSs and POBSs, GPSA replace
benchmark recovery SVG-2.
Oct 28-Nov. 8,
2019 (ship R/V Tangaroa), Wellington NZ. recover Absolute pressure gauges,
three POBSs strong motion/pressure instruments offshore of Hawkes Bay, New
Zealand studying slow slip events.
Sept. 1- 20, 2020
(ship R/V Thompson) Newport OR, testing of new compliance instruments for
monitoring of magma chamber evolution beneath Axial Volcano, Juan de Fuca
ridge.
Fall 2020 (two
cruises done remotely), R/V Sikuliaq, Seward, Alaskan GPSA.
Recent Lectures and Conferences
"Seismic
studies in the Tonga-Lau region using ocean bottom seismographs", meeting
on Dynamics of lithospheric convergence, Miyagi, Japan, Sept. 1995.
"Marine
Seismology", lecture at SIO, Oct. 1997
"A
transient electromagnetic survey of Middle Valley", lecture at SIO, Mar. 1997.
"Microearthquakes
observed on intermediate and fast spreading ridges using OBS arrays",
Summer school on active processes, Lake Myvatn, Iceland, Aug. 1997.
Event
detection and response workshop, Lynnwood Wa., Mar. 1997.
International
workshop on Scientific use of submarine cables, Okinawa, Japah, Feb. 1997.
"Ocean
Floor Seismology", lecture at Caltech, Oct.1998.
"Results
from observations of teleseismic arrivals at the TOES array spanning the 9°-10°
segment", 9°-10° Results symposium, Santa Barbara, Sept, 1998.
"Monitoring
seismicity associated with hydrothermal vent fields: lessons from the East
Pacific Rise and Juan de Fuca ridge", MOMAR meeting, Lisbon, Portugal,
Oct. 1998.
"Seismic
results from 9°50'N EPR", lecture at Lamont Doherty Earth Observatory,
Columbia University, Nov, 1998.
“Deep
Tow magnetics in Middle Valley”, lecture at Lamont Doherty Earth Observatory,
Columbia University, January, 2000.
“Long
term observations in the oceans”, Mt. Fuji, Japan. Jan. 2001
Ocean
Bottom Seismometers (OBS), Technology and Opportunities, Taipei, Taiwan, Mar.
2003
OBSIP
Annual Meeting, Woods
Hole, May 2003.
IRIS
Annual Workshop, Yosemite,
June 2003
Fall
AGU meeting, San Francisco Dec. 2003.
ORION
meeting, San Juan, Jan 2004.
Mid
Atlantic Ridge meeting, Providence, Feb. 2004.
Very
Broad Band Seismology conference, Lake Tahoe, Mar. 2004.
CATSCAN
meeting, May
2004 Calabria
Fall
AGU meeting, San Francisco Dec. 2004.
Ridge
Cyprus field trip, May 2005
Ridge
2000 meeting, Vancouver, October, 2005,
Fall
AGU meeting, San Francisco, December 2005,
ORION
Design & Implementation Workshop, SLC, March 2006
EPR
ISS science and planning meeting, LDEO, April 2006.
Fall AGU meeting, San
Francisco Dec. 2006.
“The Earth’s hum”, lecture at
Princeton U. April 2007.
Fall AGU meeting, San
Francisco Dec. 2007.
Ridge MAR Implementation
workshop, March 2008.
Ridge Spring Steering
committee meeting,
March, 2008.
Ridge Lau ISS Integration and
synthesis workshop, Sept. 2008.
Ridge EPR ISS Integration and
synthesis workshop, Sept. 2008.
Ridge Fall Steering committee
meeting, Nov.
2008.
Fall AGU meeting, San
Francisco Dec. 2008.
Earthscope Annual meeting,
May, 2009.
Ridge Annual Meeting, Oct.
2009
Margins Successor meeting,
San Antonio, Feb, 2010.
Seismological Society
Meeting. Portland, April 2010.
Experiments with Portable
Seismometers. Salt Lake City, Sept. 2010, “Ocean Pressure Sensors”
Cascadia Initiative Workshop,
Portland, Sept. 2010, “New Sensors: Bottom Pressure Sensors”
Fall AGU meeting, San
Francisco Dec. 2010.
Geoprisms Cascadia Jan. 2011,
Austin
Earthscope May, 2011, Austin
Geoprisms Alaska Workshop
Sept. 22-24, 2011Portland
Fall AGU meeting, San
Francisco Dec. 2011.
Cascadia OBS AGU pre-meeting-
2012. “Cascadia LDEO OBS Data Overview”
Fall AGU meeting, San
Francisco Dec. 2012.
New Zealand Geoprisms
Workshop, April, 15-17, 2013
LDEO MG&G seminar
“Shallow water seismology”,
Oct. 2013
IRIS OBS Workshop “Shallow
Water Seismology in Cascadia” Oct, 2013,
Fall AGU meeting, San
Francisco Dec. 2013.
Fall AGU meeting, San
Francisco Dec. 2014.
Future
Seismic and Geodetic Facility Needs in the Geosciences, Leesburg, VA, May 2015.
OBS
Symposium, presented: “Improving data on OBS horizontal components”, Vancouver,
WA. Oct. 2015.
GeoPRISMS
Theoretical and Experimental Institute on Subduction Cycles and Deformation,
Redondo Beach, Oct. 2015.
"Offshore
Geophysical Monitoring of Cascadia for Early Warning and Hazards Research"
meeting, Seattle, Mar. 2017.
"2017
OBS Symposium", Portland, ME, Sept. 18-19. Poster: "Future OBS"
Fall AGU meeting, New
Orleans, Dec. 11-15, 2017.
Meeting/visit at Kyoto U.
organized by Yoshiro Ito on seafloor geodesy/seismology, Kyoto, Jan 22-26,
talk: Columbia U (LDEO) "Marine studies of subduction zones".
Seafloor Sensors Workshop, Gleneden Beach, Oregon, July 2018, Monitoring
contemporary deformation and seismicity at the offshore Hikurangi subduction
margin.
Fall AGU meeting, Washington,
D.C., Dec. 10-14, 2018.
GeoPRISMS Synthesis &
Integration TEI, Feb 27-Mar. 1, 2019, San Antonio.
Fall
AGU meeting, San Francisco Dec. 2019.
Scientific
and monitoring priorities for cabled infrastructure offshore New Zealand,
Wellington NZ, (remotely attended), Feb 2021.
BIBLIOGRAPHY
- Spahr C. Webb
1. C. Wunsch and S. C. Webb, "The
climatology of deep ocean internal waves," J. Phys. Oceanog. 9, 235-243,
(1979).
2. T. P. Barnett, W. C. Patzert, S. C. Webb,
and B. R. Bean, "Climatological usefulness of satellite determined sea
surface temperatures in the tropical Pacific," Bull. Amer. Meteor. Soc.
60, 197-205 (1979).
3. S. C. Webb and S. C. Cox,
"Electromagnetic field induced at the seafloor by Rayleigh-Stoneley
waves," J. Geophys. Res. 87, 4093-4102 (1982).
4. C. S. Cox and S. C. Webb, "CMOS
measurement system detects seismic activity on the seabed," Digital
Design,13 (7), 68-69 (1983).
5. C. S. Cox, T. Deaton, and S. C. Webb, "A deep sea differential pressure gauge," J. Atm. Oceanic
Tech. 1, (3), 237-246 (1984).
6. S. C. Webb and C. S. Cox, "Pressure and
electric fluctuations on the deep seafloor: Background noise for seismic
detection," Geophys. Res. Lett. 11 (10), 967-970, (1984).
7. S. C. Webb, S. C. Constable, C. S. Cox, and
T. Deaton, "A sea floor electric field instrument," J.
Geomag. Geoelectr. 37, 1115-1125 (1985).
8. S. C. Webb and C. S. Cox, "Observations
and modeling of seafloor microseisms," J. Geophys. Res. 91, 7343-7358,
(1986).
9. S. C. Webb, "Coherent pressure
fluctuations observed at two sites on the deep sea
floor," Geophys. Res. Lett. 13 (1), 141-144 (1986).
10. C. S. Cox, S. C. Constable, A. D. Chave, and
S. C. Webb, "Controlled source electromagnetic sounding of the oceanic
lithosphere," Nature 320, 52-54 (1986).
11. S. C. Webb and S. C. Constable,
"Microseism propagation between two sites on the deep seafloor,"
Bull. Soc. Seismol. Amer. 76 (5), 1433-1445 (1986).
12. Spahr C. Webb, "Long period acoustic and
seismic measurements and ocean floor currents," IEEE J. Oceanic Eng. 13,
263-270 (1988).
13. S. C. Webb , X. Zhang,
and W.C. Crawford, "Infragravity waves in the deep ocean," J.
Geophys. Res. 96, 2723-2736 (1991).
14.
Crawford, Wayne C., S.C. Webb, and J.A. Hildebrand, "Seafloor compliance
observed by long period pressure and displacement measurements," J.
Geophys. Res. 96, 16,151-16,160 (1991).
15. John Hildebrand, Spahr Webb, and LeRoy
Dorman, "Monitoring ridge crest activity with ocean bottom
microseismicity," Ridge Events Newsletter 2, 6-8 (1991).
16. S. C. Webb and A. Schultz, "Very low
frequency ambient noise at the seafloor under the Beaufort Sea ice cap,"
J. Acoust. Soc. Am. 91, 1429-1439 (1992).
17. Spahr C. Webb, "The equilibrium oceanic
microseism spectrum," J. Acoust. Soc. Am. 94, 2141-2158 (1992).
18. S. C. Webb, R. N. Edwards, and L. Yu, "First measurements from a deep tow transient sounding system,"
Mar. Geophys. Res. 15(1), 13-26 (1993).
19. M. A. McDonald, J. A. Hildebrand, and S. C. Webb, "Seismic
structure and anisotropy of the Juan de Fuca Ridge at 45°N," J. Geophys.
Res. 99(B3), 4857-4873 (1994).
20. S. C. Webb, W. C. Crawford, and J. A.
Hildebrand, "Long period seismometer deployed at OSN-1," OSN-1
Newsletter- Seismic Waves 3(1), 4-6 (1994).
21. R. A. Sohn, J. A. Hildebrand, S. C. Webb, and
C. G. Fox, "Hydrothermal microseismicity
at the Megaplume site on the southern Juan de Fuca Ridge," Bull. Seism.
Soc. Am., 85(3), 775-786, (1995) .
22. M. A. McDonald, J. A. Hildebrand, and S. C.
Webb, "Blue and fin whales observed on a seafloor array in the Northeast
Pacific," J. Acoust. Soc. Am., 98(2), 712-721, (1995).
23. S. C. Webb and R. N. Edwards, "On the
correlation of electrical conductivity and heat flow in Middle Valley," J.
Geophys. Res., 100(B11), 22523-22535, (1995).
24.
Hildebrand, J.A., M.A. McDonald, and
S.C. Webb, "Microearthquakes at
intermediate spreading-rate ridges: The cleft segment megaplume site on the
Juan de Fuca ridge", Bull. Seismo. Soc. Amer., 87, 684-691, (1997)
25.
Zhao, D.P., Y. Xu, D.A. Wiens, L.M.
Dorman, J.A. Hildebrand, and S.C. Webb, "Depth extent of the Lau back-arc
spreading center and its relation to subduction processes", Science, 278,
254-257, (1997).
26.
Sohn, R.A., S.C. Webb, J.A. Hildebrand,
and B.D. Cornuelle,
"Three-dimensional tomographic velocity structure of upper crust, CoAxial segment,
Juan de Fuca ridge: Implications for on-axis evolution and hydrothermal
circulation", J.
Geophys. Res., 102, 17679-17695, (1997)
27.
Webb, S.C. “Broadband seismology and noise under the ocean”, Rev. of
Geophysics, 36, 105-142., (1998).
28.
Forsyth, DW; Scheirer, DS; Webb, SC; Dorman, LM; and others, "Imaging the
deep seismic structure beneath a mid-ocean ridge: The MELT experiment",
Science, 280, 1215-1218, (1998).
29.
Webb, S.C., and D.W. Forsyth,
"Structure of the upper mantle under the EPR from waveform inversion of
regional events",
Science, 280, 1227-1229, (1998).
30.
Forsyth, D.W. and S.C. Webb, L.M.
Dorman, and Y. Shen, "Phase velocities of Rayleigh waves in the
MELT experiment on the East Pacific Rise", Science, 280, 1235-1238, (1998).
31.
Sohn, RA, J.A. Hildebrand, and S.C.
Webb, "Postrifting seismicity and a model for the 1993 diking event on the CoAxial segment,
Juan de Fuca ridge.", J.. Geophys. Res., 103, 9867-9877, (1998).
32.
Crawford, W.C., S.C. Webb, and J.A. Hildebrand, "Estimating shear
velocities in the oceanic crust from compliance measurements by two-dimensional
finite difference modeling", J. Geophys. Res., 103, 9895-9916, (1998).
33.
Evans, R.L., S.C. Webb, M. Jegen, and K. Sananikone, Hydrothermal circulation
at the Cleft-Vance overlapping spreading center: results from a magnetometric
resistivity survey",
J. Geophys. Res., 103, 12321-12338, (1998).
34.
Aroyan, J.L., McDonald, M.A., S.C. Webb, J.A. Hildebrand. D. Clark, J.S.
Reidenberg, and J.T.
Laitman, Acoustic Models of Sound
Production and Propagation, in Hearing
by Whales and Dolphins, Au W., Popper, A.N. and Fay, R.L. eds, Springer-Verlag, NY, pp 485, (2000).
35.
Ballu, V.S., J.A. Hildebrand, S.C. Webb, Seafloor gravity evidence for hydrothermal
alteration of the sediments in Middle Valley, Juan de Fuca ridge, Marine
Geology, 150, 99-111, (1998).
36.
Crawford, W.C., S.C. Webb and J.A. Hildebrand, Constraints on melt in the lower
crust and Moho at the East Pacific Rise, 9°48'N, using seafloor compliance, J.
Geophys. Res., 104(B2), 2923-2939 , (1999).
37.
Roth, E.G., D.A. Wiens, L.M. Dorman, S.C. Webb, and J. Hildebrand, Seismic
attenuation tomography of the Tonga-Fiji region using phase pair arrivals, J. Geophys.
Res., 104(B4), 4795-4810, (1999).
38.
Koper, K.D., D.A. Wiens, L.M. Dorman, J.A. Hildebrand, S.C. Webb, Modeling the
Tonga Slab: can travel time resolve a metastable olivine wedge?, J. Geophys. Res., 103(B12), 30079-30100,
(1998).
39.
Sohn, R.A., D.J. Fornari, K.L. VonDamm, J.A. Hildebrand, S.C. Webb, Seismic,
thermal, and chemical evidence for a propagating hydrothermal cracking event on
the East Pacific Rise, (9° 50'N), Nature, 396, 159-161, (1998).
40.
Wilcock, W.S., S.C. Webb, and I. Bjarnason, The effect of local wind on seismic
noise near 1 Hz, and local wind at the MELT site and on Iceland, Bull. Seismo.
Soc. Amer., 89(6),
1543-1557, (1999).
41.
Sohn, R.A., J.A. Hildebrand and S.C. Webb, A microearthquake study of the high
temperature vent fields on volcanically active East Pacific Rise at 9°50'N, J.
Geophys. Res., 104(B11), 25367-25377, (1999).
42.
Webb, S.C. and W.C. Crawford,
Long period seafloor seismology and deformation under ocean
waves, Bull. Seismo. Soc. Amer., 89(6), 1535-1542, (1999).
43.
Sohn, R.A., W.C. Crawford, and S.C. Webb, Local seismicity following the 1998
eruption of Axial Volcano, Geophys. Res. Lett., 26(23), 3433-3436, (1999).
44.
Koper, K.D., D.A. Wiens, L.M. Dorman, J.A. Hildebrand, S.C. Webb, Constraints
on the origin of slab and mantle wedge anomalies in Tonga from the ratio of S
to P velocities, J.
Geophys. Res., 104(B7), 15089-15104, (1999).
45.
Crawford, W.C., and S.C. Webb, Removing tilt noise from low frequency (<0.1
Hz) seafloor vertical seismic data, Bull. Seismo. Soc. Amer., 90(4), 952-963,
(2000).
46.
Webb, Spahr C., and W. H. K. Lee. "Seismic noise on land and on the
seafloor." INTERNATIONAL GEOPHYSICS SERIES 81, no. A (2002):
305-318.
47. Sohn, R. A., F. Vernon,
J. A. Hildebrand, and
S. C. Webb, Field measurements of sonic boom penetration into the ocean, J.
Acoust. Soc. Amer., 107(6), 3073- 3083, (2000).
48. Golden, C.E., S.C. Webb,
and R.A. Sohn, Hydrothermal microearthquake swarms beneath active vents at
Middle Valley, Juan de Fuca Ridge, J. Geophys. Res., 108 (B1), 2027,
doi:10.1029/2001JB000226, 2003
49. Crawford, W.C. and S.C.
Webb, Variations in the distribution of magma in the lower crust and at the
Moho beneath the East Pacific Rise at 9-10N, Earth Planet Sci. Lett., 203(1), 117-130, 2002.
50. Webb, S.C. T.K. Deaton,
and J.C. Lemire, A broadband ocean bottom seismometer system based
on a 1 Hz natural period geophone, Bull. Seismo. Soc. Amer., 91 (2),
304-312, (2001).
51.Gilbert,
H.J., A.F. Sheenan, D.A. Wiens, L. Dorman, J. Hildebrand, and S.C. Webb, Upper
mantle discontinuity structure in the region of the Tonga subduction zone,
Geophys. Res. Lett., 28(9), 1855-1858, (2001).
52. Crawford, W.C., J.A.
Hildebrand, D.A. Wiens, S.C. Webb, and L.M. Dorman, Tonga Ridge and Lau Basin
crustal structure from seismic refraction data, , J. Geophys. Res., 108, (B4),
10.1029/2001JB001435, (2003).
53.
Gee, J.S., S.C. Webb, J. Ridgway, H. Staudigel, and M.A. Zumberge, A deep-tow
magnetic survey of Middle Valley, Juan de Fuca ridge, Geochem., Geophys., Geosyst., 2, 10.1029/2001GC000170,
(2001).
54.
Smith, G.P., D.A. Wiens, K.M. Fischer, L.M. Dorman, S.C. Webb, and J.A.
Hildebrand, A complex pattern of mantle flow in the Lau backarc, Science, 292,
713-716, (2001).
55.
West, M., W. Menke, M. Tolstoy, S. Webb. and R. Sohn, Magma storage beneath
Axial Volcano on the Juan de Fuca mid-ocean ridge, Nature, 413, 833-836, (2001).
56.
Evans, R.L., S.C. Webb and others, Crustal resistivity structure at 9° 50’N on
the East Pacific Rise: preliminary results of an electromagnetic survey,
Geophys. Res. Lett., 29(6), 4 pages,. (2002).
57.
Sohn, R.A., A.H. Barclay, and S.C. Webb, Microearthquake patterns following the
1998 eruption of Axial Volcano, Juan de Fuca Ridge: Mechanical Relaxation and
thermal strain, J. Geophys. Res., 109, B01101,
doi:10.1029/2003JB002499, (2004).
58.
Sohn, R.A., S.C. Webb and J.A. Hildebrand, Fine scale seismic structure of the
shallow volcanic crust on the East Pacific Rise at 9-50N, J. Geophys. Res.,
109, B12104, doi:101029/2004JB003152, (2004).
59.
Tolstoy, M., J. B. Diebold, S. C. Webb, D. R. Bohnenstiehl, E. Chapp, R. C.
Holmes, and M. Rawson, Broadband calibration of R//V Ewing seismic sources,
Geophys. Res. Lett., 31, L14310, doi:10.1029/2004GL020234 (2004).
60.
Harmon, N., D.W. Forsyth, K.M. Fischer, and S.C. Webb, Variations in shear-wave
splitting in young pacific seafloor, Geophys. Res. Lett., 31, L15609,
doi:10.1029/2004GL020495, (2004).
61.
Gu, Y. J., S.C. Webb, A. LernerLam, and J.B. Gaherty, Upper mantle structure beneath the eastern
Pacific ocean ridges, J. Geophys. Res., 110, B06305, doi:10.1029/2004/JB003381, (2005).
62.
Harmon, N., D.W. Forsyth, R. Lamm, and S.C. Webb, P and S wave delays beneath
intraplate volcanic ridges and gravity lineations near the East Pacific Rise, J. Geophys. Res., 112(B3), B03309, doi: 10.1029/2006JB004392, (2007).
63.
Weerarante, D S., D.W. Forsyth, Y. Yang and, S.C. Webb, Rayleigh wave tomography of the
oceanic mantle beneath intraplate volcanic ridges in the South Pacific, J.
Geophys. Res., 112, B6, B06303, doi: 10.1029/2006JB004403, (2007).
64.
Webb, S.C., “The Earth's Hum is Driven by Ocean Waves over the Continental
Shelves”, Nature, 445, 754-756, (2007).
65.
Holmes, R.C., S.C. Webb and D.W. Forsyth, Crustal structure beneath gravity
lineations in the GLIMPSE study are from seismic refraction data, J. Geophys.
Res., 112, B07316, doi:10.1029/2006JB004685, (2007).
66.
Harmon, N., D.W. Forsyth, and S.C. Webb, Using ambient seismic noise to
determine short period phase velocities and shallow shear velocities in young
oceanic lithosphere, Bull. Soc. Seism. Amer, 97(6), 2009-2023, (2007).
67.
Webb, S.C., The Earth’s hum: the excitation of Earth normal modes by ocean
waves, J. Geophys. Int., 174(3),
542-566, doi:10.1111/j.1365-246X.2008.03801.x, (2008).
68.
Crawford, W.C., J.A. Hildebrand, S.C. Webb, R.A. Sohn, and C. Golden, Sediment
shear moduli at two sites off of the California coast from seafloor compliance
measurements, in prep, (2008).
69.
Ekstrom, G., G.A. Abers, and S.C. Webb, Determination of surface wave phase
velocities across USArray from noise and Aki’s spectral formulation, Geophys. Res. Lett., L18301,
doi:10.1029/2009GL039131, (2009).
70. Tolstoy, M., J.
Diebold, L. Doermann, S. Nooner, S. C. Webb, D. R. Bohnenstiehl, T. J. Crone,
and R. C. Holmes (2009), Broadband calibration of the R/V Marcus G. Langseth
four-string seismic sources, Geochem.
Geophys. Geosyst., 10, Q08011, doi:10.1029/2009GC002451, (2009).
71.
Webb, S.C. and W.C. Crawford, Shallow Water Broad Band OBS Seismology, Bull. Seism.
Soc. Amer., 100(4), 1770-1778, doi: 10.1785/012009020, (2010).
72.
Diebold, J.B., M. Tolstoy, L. Doermann, S.L. Nooner and S. C. Webb, Marcus G.
Langseth seismic source modeling and calibration, Geochem. Geophys. Geosyst., 11, Q12012, 20 PP.,
doi:10.1029/2010GC003216, (2010).
73.
Harmon, N., D. W. Forsyth, D. S. Weeraratne, Y., Yang, and S. C. Webb, Mantle
heterogeneity and off axis volcanism on young pacific lithosphere. Earth and Planetary Science Letters,
311(3-4), 306-315, http://dx.doi.org/10.1016/j.epsl.2011.09.038
,(2011).
74.
Zha, Y., S. C. Webb, and W. Menke,
Determining the orientations of ocean bottom seismometers using ambient noise
correlation, Geophys. Res. Lett., 40, doi:10.1002/grl.50698, (2013).
75. Zha, Y., S. C. Webb, S.L. Nooner and W.C. Crawford, Spatial
distribution and temporal evolution of crustal melt distribution beneath the
East Pacific Rise at 9º-10º N inferred from 3D seafloor compliance modeling, J. Geophys.
Res., (2014).
76.
Scott L. Nooner, Spahr C. Webb, W. Roger Buck, and Marie-Helen Cormier,
Post-Eruption Inflation of the East Pacific Rise at 9º50' N, Geochem. Geophys. Geosyst., (2014).
77. Kuo, B. Y., Webb, S. C., Lin, C. R., Liang,
W. T., & Hsiao, N. C. Removing Infragravity‐Wave‐Induced Noise from Ocean‐Bottom Seismographs (OBS) Data Deployed Offshore of
Taiwan. Bulletin of the Seismological Society of America. (2014).
78.
Zha, Yang, Spahr C. Webb, S. Shawn Wei, Douglas A. Wiens, Donna K. Blackman,
William Menke, Robert A. Dunn, and James A. Conder, Seismological imaging of
ridge–arc interaction beneath the Eastern Lau Spreading Center from OBS ambient
noise tomography, Earth and Planet. Science Letters, 408, 194-206,
(2014).
79.
Menke, W., Zha, Y., Webb, S. C., and Blackman, D. K. Seismic Anisotropy
Indicates Ridge‐parallel
Asthenospheric Flow Beneath the Eastern Lau Spreading Center. J. Geophys .R, 120(2), 976-992, (2015).
80.
Wei, S. Shawn, D.A. Wiens, Y. Zha, T. Plank, S.C. Webb, D.K. Blackman, R.A.
Dunn. and J.A. Conder, Seismic evidence of effects of water on melt transport
in the Lau back-arc mantle, Nature, doi:10.1038/nature14113,
(2015).
81.
Shillington, Donna J. , Anne Bécel, Mladen R.
Nedimović, Harold Kuehn, Spahr C. Webb, Geoffrey A. Abers, Katie M. Keranen,
Jiyao Li, Matthias Delescluse, Gabriel A. Mattei-Salicrup, Controls on abrupt
variations in faulting, hydration and seismicity in the Alaska subduction zone,
Nature Geoscience, DOI:10.1038/ngeo2586, (2015).
82. Li, Jiyao, Donna J.
Shillington, Anne Bécel, Mladen R. Nedimović, Spahr C. Webb, Demian M. Saffer,
Katie M. Keranen, and Harold Kuehn. Downdip variations in seismic reflection
character: Implications for fault structure and seismogenic behavior in the
Alaska subduction zone. Journal of Geophysical Research: Solid Earth
120, no. 11 7883-7904, (2015).
83. Kuo, Ban‐Yuan, Wayne C. Crawford,
Spahr C. Webb, Ching‐Ren
Lin, Tai‐Chieh
Yu, and Liwen Chen. Faulting and hydration of the upper crust of the SW Okinawa
Trough during continental rifting: Evidence from seafloor compliance inversion.
Geophysical Research Letters 42, 12, 4809-4815, (2015).
84. Webb, S.C., and S.L.
Nooner, High Resolution Seafloor Absolute Pressure Gauge
Measurements Using a Better Counting Method, Journal of Atmospheric and Oceanic Technology, 33(9), 1859-1874, (2016).
85. Zha, Y. and Webb, S.C.,
Crustal shear velocity structure in the Southern Lau Basin constrained by
seafloor compliance. Journal of Geophysical Research: Solid Earth, 121(5),
pp.3220-3237, (2016).
86.
Wallace, Laura, M. Spahr C. Webb, Yoshihiro Ito, Kimihiro Mochizuki, Ryota
Hino, Stuart Henrys, Susan Y. Schwartz, Anne F. Sheehan, Slow slip near the
trench at the Hikurangi subduction zone, New Zealand, Science, 352, no. 6286, 701-704 (2016).
87.
Harris, Robert, Laura Wallace, Spahr C. Webb, Yoshihiro Ito, Kimihiro
Mochizuki, Hiroshi Ichihara, Stuart Henrys, Anne Tréhu, Susan Schwartz, Anne
Sheehan, Demian Saffer, and Rachel Lauer, Investigations of shallow slow slip offshore
of New Zealand, Eos, 97, doi:10.1029/2016EO048945. (2016).
88. Wei, S. S., Y. Zha, W. Shen, D. A. Wiens, J. A. Conder, and S. C. Webb, Upper mantle structure of the Tonga-Lau-Fiji region from Rayleigh wave tomography, Geochem. Geophys. Geosyst., 17, doi
Li,
Jiyao, Donna J. Shillington, Demian M. Saffer, Anne Bécel, Mladen R. Nedimović,
Harold Kuehn, Spahr C. Webb, Katie M. Keranen, and Geoffrey A. Abers.
Connections between subducted sediment, pore-fluid pressure, and earthquake
behavior along the Alaska megathrust. Geology (2018).
91. Todd, E.K., Schwartz,
S.Y., Mochizuki, K., Wallace, L.M., Sheehan, A.F., Webb, S.C., Williams, C.A.,
Nakai, J., Yarce, J., Fry, B. and Henrys, S.,.
Earthquakes and Tremor Linked to Seamount Subduction During Shallow Slow Slip
at the Hikurangi Margin, New Zealand. Journal of Geophysical Research: Solid
Earth, (2018).
92. Muramoto, T., Ito, Y.,
Inazu, D., Wallace, L.M., Hino, R., Suzuki, S., Webb, S.C. and Henrys, S.
Seafloor crustal deformation on ocean bottom pressure records with non‐tidal variability
corrections: application to Hikurangi margin, New Zealand. Geophysical
Research Letters, (2019).
93. Yarce, J., Sheehan, A.F.,
Nakai, J.S., Schwartz, S.Y., Mochizuki, K., Savage, M.K., Wallace, L.M.,
Henrys, S.A., Webb, S.C., Ito, Y. and Abercrombie, R.E. Seismicity at the
northern Hikurangi Margin, New Zealand, and investigation of the potential
spatial and temporal relationships with a shallow slow slip event. Journal
of Geophysical Research: Solid Earth, (2019).
94. Warren-Smith, E., B. Fry,
L. Wallace, E. Chon, S. A. Henrys, A. F. Sheehan, K. Mochizuki, S. Y. Schwartz,
S.C. Webb and S. Lebedev, Episodic stress and fluid pressure cycling in
subducting oceanic crust during slow slip, Journal of Geophysical Research:
Solid Earth, doi:10.1038/s41561-019-0367-x, (2019).
95.
Zal, H. J., K. Jacobs, M.K. Savage, J.Yarce, S.
Mroczek, K. Graham, E.K. Todd, J. Nakai, Y. Iwasaki, A. Sheehan, K. Mochizuki,
L. Wallace, S. Schwartz, S. C. Webb, and
S. Henrys, 2019, Temporal
and spatial variations in seismic anisotropy and VP/VS ratios in a region of slow slip, Earth and Planetary Sciences Letters,
2020 Feb 15;532:115970.
96. Ito, Y., Webb, S.C.,
Kaneko, Y., Wallace, L.M. and Hino, R., 2020. Sea surface gravity waves excited
by dynamic ground motions from large regional earthquakes. Seismological
Research Letters, 91(4), pp.2268-2277.
97.
Abers GA, Adams AN, Haeussler PJ, Roland E, Shore PJ, Wiens DA, Schwartz SY,
Sheehan AF, Shillington DJ, Webb S, Worthington LL. Understanding Alaska’s
Earthquakes. Eos. 2019 Oct;100(10).
98.
Inoue, T., Ito, Y., Wallace, L.M.,
Yoshikawa, Y., Inazu, D., Garcia, E.S.M., Muramoto, T., Webb, S.C., Ohta, K.,
Suzuki, S. and Hino, R., 2021. Water Depth Dependence of Long‐Range Correlation in
Nontidal Variations in Seafloor Pressure. Geophysical Research Letters, 48(8),
2020GL092173.
Scripps Institution of
Oceanography Reference Series
1. S. C. Webb, P. L. Gruber, L. W. Hart, and D.
S. Luther, "Appendix
E - Ocean induced fields working group report," Report of Workshop on the
Geoelectric and Geomagnetic Environment of Continental Margins, SIO Reference
90-20, Scripps Institution of Oceanography, Marine Physical Laboratory, San
Diego, CA, 37 pgs (1990). Final Report for ONR Grant N00014-89-J-3064.
Technical
and Miscellaneous Reports
1.
Chave et al., Report of a workshop on technical Approaches to construction of a
seafloor geomagnetic observatory, Wood Hole Oceanographic Institution, Tech.
Rep. 95-12, pp 47, 1995.
Thesis
1. S. C. Webb, "Observations of seafloor
pressure and electric field fluctuations," Ph.D. Thesis, University of
California, San Diego, (1984).