Susan Schwartz

Last updated
Susan Y. Schwartz
Alma materUniversity of Michigan
Scientific career
InstitutionsUniversity of California, Santa Cruz
Thesis Fault zone heterogeneity and earthquake occurrence in subduction zones  (1988)

Susan Y. Schwartz is a scientist at the University of California, Santa Cruz known for her research on earthquakes, through field projects conducted in locations in Costa Rica and the San Andreas Fault.

Contents

Education and career

Schwartz has an Sc.B. from Brown University (1981) and an M.S. (1983) [1] and a Ph.D. (1988) from the University of Michigan. [2] [3] During her Ph.D., she worked on the occurrence of earthquakes in subduction zones, including the Solomon Islands, the 1968 Tokachi earthquake, and the southern Kuril Islands. [4] At the University of California in Santa Cruz, Schwartz was first a postdoctoral fellow from 1988 until 1990, followed by four years as an assistant research seismologist, and then in 1994 she was hired as an assistant professor and was subsequently promoted to professor in 2002. [3]

In 2016 Schwartz was elected a fellow of the American Geophysical Union who cited her "for fundamental work that places subduction zone earthquakes in tectonic context". [5]

Research

Schwartz's research interests center on the mechanics of earthquakes in subduction zones and variations in earthquakes on regional scales. While at the University of Michigan, she worked on paleomagnetism in the Wyoming-Idaho region [6] and the folding of the Appalachian Mountains. [7] Her research has taken her to multiple field locations including the Southern Kurile Islands, [8] [9] New Zealand, [10] [11] and Costa Rica. [12] [13] Her research on the 2012 Costa Rica earthquake relied on instrumentation installed in the region prior to the earthquake [13] [14] which allowed her to define spatial variability in the fluids beneath the plate that impact the formation of earthquakes in the region. [15] She has also examined the seismology of the 1971 Solomon Islands earthquakes. [16] Schwartz was a postdoc working in California during the 1989 Loma Prieta earthquake [17] [18] and in 2014 she recalled her feelings during the day of the earthquake and her realization of the importance of the "human element" of her research in seismology. [19]

Selected publications

Awards and honors

Related Research Articles

<span class="mw-page-title-main">Intraplate earthquake</span> Earthquake that occurs within the interior of a tectonic plate

The term intraplate earthquake refers to a variety of earthquake that occurs within the interior of a tectonic plate; this stands in contrast to an interplate earthquake, which occurs at the boundary of a tectonic plate. Intraplate earthquakes are often called "intraslab earthquakes," especially when occurring in microplates.

Earthquake prediction is a branch of the science of seismology concerned with the specification of the time, location, and magnitude of future earthquakes within stated limits, and particularly "the determination of parameters for the next strong earthquake to occur in a region". Earthquake prediction is sometimes distinguished from earthquake forecasting, which can be defined as the probabilistic assessment of general earthquake hazard, including the frequency and magnitude of damaging earthquakes in a given area over years or decades. Not all scientists distinguish "prediction" and "forecast", but the distinction is useful.

A seismic gap is a segment of an active fault known to produce significant earthquakes that has not slipped in an unusually long time, compared with other segments along the same structure. There is a hypothesis or theory that states that over long periods, the displacement on any segment must be equal to that experienced by all the other parts of the fault. Any large and longstanding gap is, therefore, considered to be the fault segment most likely to suffer future earthquakes.

<span class="mw-page-title-main">Wadati–Benioff zone</span> Planar zone of seismicity corresponding with the down-going slab

A Wadati–Benioff zone is a planar zone of seismicity corresponding with the down-going slab in a subduction zone. Differential motion along the zone produces numerous earthquakes, the foci of which may be as deep as about 670 km (420 mi). The term was named for the two seismologists, Hugo Benioff of the California Institute of Technology and Kiyoo Wadati of the Japan Meteorological Agency, who independently discovered the zones.

<span class="mw-page-title-main">Aseismic creep</span> Surface displacement along a geological fault without earthquakes occurring

In geology, aseismic creep or fault creep is measurable surface displacement along a fault in the absence of notable earthquakes. Aseismic creep may also occur as "after-slip" days to years after an earthquake. Notable examples of aseismic slip include faults in California.

A slow earthquake is a discontinuous, earthquake-like event that releases energy over a period of hours to months, rather than the seconds to minutes characteristic of a typical earthquake. First detected using long term strain measurements, most slow earthquakes now appear to be accompanied by fluid flow and related tremor, which can be detected and approximately located using seismometer data filtered appropriately. That is, they are quiet compared to a regular earthquake, but not "silent" as described in the past.

Episodic tremor and slip (ETS) is a seismological phenomenon observed in some subduction zones that is characterized by non-earthquake seismic rumbling, or tremor, and slow slip along the plate interface. Slow slip events are distinguished from earthquakes by their propagation speed and focus. In slow slip events, there is an apparent reversal of crustal motion, although the fault motion remains consistent with the direction of subduction. ETS events themselves are imperceptible to human beings and do not cause damage.

<span class="mw-page-title-main">Molucca Sea Plate</span> Small fully subducted tectonic plate near Indonesia

Located in the western Pacific Ocean near Indonesia, the Molucca Sea Plate has been classified by scientists as a fully subducted microplate that is part of the Molucca Sea Collision Complex. The Molucca Sea Plate represents the only known example of divergent double subduction (DDS), which describes the subduction on both sides of a single oceanic plate.

The South Bismarck Plate is a small tectonic plate located mainly in the southern Bismarck Sea. The eastern part of New Guinea and the island of New Britain are on this plate. It is associated with high earthquake and volcanic activity as part of the New Britain subduction zone within the Pacific Ring of Fire.

In seismology, doublet earthquakes – and more generally, multiplet earthquakes – were originally identified as multiple earthquakes with nearly identical waveforms originating from the same location. They are now characterized as single earthquakes having two main shocks of similar magnitude, sometimes occurring within tens of seconds, but sometimes separated by years. The similarity of magnitude – often within 0.4 magnitude – distinguishes multiplet events from aftershocks, which start at about 1.2 magnitude less than the parent shock and decrease in magnitude and frequency according to known laws.

<span class="mw-page-title-main">North Island Fault System</span> Fault zone of the east coast of New Zealands North Island

The North Island Fault System (NIFS) is a set of southwest–northeast trending seismically-active faults in the North Island of New Zealand that carry much of the dextral strike-slip component of the oblique convergence of the Pacific Plate with the Australian Plate. However despite at least 3 km (1.9 mi) of uplift of the axial ranges in the middle regions of the fault system during the last 10 million years most of the shortening on this part of the Hikurangi Margin is accommodated by subduction.

<span class="mw-page-title-main">Hikurangi Margin</span> Subduction zone off the east coast of New Zealands North Island

The Hikurangi Margin is New Zealand's largest subduction zone and fault.

<span class="mw-page-title-main">Flat slab subduction</span> Subduction characterized by a low subduction angle

Flat slab subduction is characterized by a low subduction angle beyond the seismogenic layer and a resumption of normal subduction far from the trench. A slab refers to the subducting lower plate. A broader definition of flat slab subduction includes any shallowly dipping lower plate, as in western Mexico. Flat slab subduction is associated with the pinching out of the asthenosphere, an inland migration of arc magmatism, and an eventual cessation of arc magmatism. The coupling of the flat slab to the upper plate is thought to change the style of deformation occurring on the upper plate's surface and form basement-cored uplifts like the Rocky Mountains. The flat slab also may hydrate the lower continental lithosphere and be involved in the formation of economically important ore deposits. During the subduction, a flat slab itself may deform or buckle, causing sedimentary hiatus in marine sediments on the slab. The failure of a flat slab is associated with ignimbritic volcanism and the reverse migration of arc volcanism. Multiple working hypotheses about the cause of flat slabs are subduction of thick, buoyant oceanic crust (15–20 km) and trench rollback accompanying a rapidly overriding upper plate and enhanced trench suction. The west coast of South America has two of the largest flat slab subduction zones. Flat slab subduction is occurring at 10% of subduction zones.

<span class="mw-page-title-main">Laura Wallace</span> American geophysicist

Laura Martin Wallace is a geodetic principal scientist who works between the University of Texas at Austin and GNS Science in New Zealand. She was elected Fellow of the Royal Society Te Apārangi in 2018.

An earthquake occurred on 26 August 2012 at 22:37 local time. The earthquake located off the coast of El Salvador measured 7.3 on the moment magnitude scale and had a focal depth of 16.0 kilometres (10 mi). No deaths were reported, however more than 40 people were injured when they were caught in a tsunami generated by the earthquake. Waves from the tsunami were unusually large for an earthquake of this size. The large waves were attributed to the earthquake's unique rupture characteristic. In addition to the absence of fatalities, damage caused by the earthquake and tsunami was minimal as a result of the sparse population around the affected region and the slow rupture characteristic of the event.

Anne Sheehan is a geologist known for her research using seismometer data to examine changes in the Earth's crust and mantle.

Donna Eberhart-Phillips is a geologist known for her research on subduction zones, especially in Alaska and New Zealand.

<span class="mw-page-title-main">Oblique subduction</span> Tectonic process

Oblique subduction is a form of subduction for which the convergence direction differs from 90° to the plate boundary. Most convergent boundaries involve oblique subduction, particularly in the Ring of Fire including the Ryukyu, Aleutian, Central America and Chile subduction zones. In general, the obliquity angle is between 15° and 30°. Subduction zones with high obliquity angles include Sunda trench and Ryukyu arc.

<span class="mw-page-title-main">Earthquake cycle</span>

The earthquake cycle refers to the phenomenon that earthquakes repeatedly occur on the same fault as the result of continual stress accumulation and periodic stress release. Earthquake cycles can occur on a variety of faults including subduction zones and continental faults. Depending on the size of the earthquake, an earthquake cycle can last decades, centuries, or longer. The Parkfield portion of the San Andreas fault is a well-known example where similarly located M6.0 earthquakes have been instrumentally recorded every 30–40 years.

Susan Marian Ellis is a geophysicist based in New Zealand, who specialises in modelling the geodynamics of the Earth's crust deformation, at different scales. Ellis is a principal scientist at GNS Science and her main interests are in subduction, seismology, tectonics, crust and petrology. Ellis's current work focuses on the influence of faulting on stresses in the crust, and how this is related to geological hazard and the tectonic settings in New Zealand.

References

  1. ↑ Schwartz, Susan Y; Van der Voo, R; University of Michigan; Department of Geological Sciences (1983). A paleomagnetic study of the thrust sheet rotations in response to foreland impingement in the Wyoming-Idaho overthrust belt: [manuscript in lieu of thesis, Master of Science in Geology. OCLC   1019536020.
  2. ↑ "Earth & Planetary Sciences Faculty". eps.ucsc.edu. Retrieved 2021-09-06.
  3. 1 2 "Susan Schwartz | IRIS". www.iris.edu. Retrieved 2021-09-06.
  4. ↑ SCHWARTZ, SUSAN Y (1988). Fault zone heterogeneity and earthquake occurrence in subduction zones (Thesis). OCLC   244028973.
  5. 1 2 "Schwartz". Honors Program. Retrieved 2021-09-06.
  6. ↑ Schwartz, Susan Y.; Voo, Rob Van der (1984). "Paleomagnetic study of thrust sheet rotation during foreland impingement in the Wyoming-Idaho overthrust belt". Journal of Geophysical Research: Solid Earth. 89 (B12): 10077–10086. Bibcode:1984JGR....8910077S. doi:10.1029/JB089iB12p10077. ISSN   2156-2202.
  7. ↑ Schwartz, Susan Y.; Voo, Rob Van der (1983). "Paleomagnetic evaluation of the Orocline Hypothesis in the central and southern Appalachians". Geophysical Research Letters. 10 (7): 505–508. Bibcode:1983GeoRL..10..505S. doi:10.1029/GL010i007p00505. ISSN   1944-8007.
  8. ↑ Schwartz, Susan Y.; Dewey, James W.; Lay, Thorne (1989). "Influence of fault plane heterogeneity on the seismic behavior in the Southern Kurile Islands Arc". Journal of Geophysical Research. 94 (B5): 5637. Bibcode:1989JGR....94.5637S. doi:10.1029/JB094iB05p05637. ISSN   0148-0227.
  9. ↑ Schwartz, Susan Y.; Ruff, Larry J. (1987). "Asperity distribution and earthquake occurrence in the southern Kurile Islands arc". Physics of the Earth and Planetary Interiors. 49 (1–2): 54–77. Bibcode:1987PEPI...49...54S. doi:10.1016/0031-9201(87)90132-4. hdl: 2027.42/26509 .
  10. ↑ Wallace, L. M.; Webb, S. C.; Ito, Y.; Mochizuki, K.; Hino, R.; Henrys, S.; Schwartz, S. Y.; Sheehan, A. F. (2016-05-06). "Slow slip near the trench at the Hikurangi subduction zone, New Zealand". Science. 352 (6286): 701–704. Bibcode:2016Sci...352..701W. doi: 10.1126/science.aaf2349 . ISSN   0036-8075. PMID   27151867. S2CID   206647253.
  11. ↑ Todd, Erin K.; Schwartz, Susan Y. (December 2016). "Tectonic tremor along the northern Hikurangi Margin, New Zealand, between 2010 and 2015". Journal of Geophysical Research: Solid Earth. 121 (12): 8706–8719. doi: 10.1002/2016JB013480 .
  12. ↑ Hagerty, M.T.; Schwartz, S.Y.; Garcés, M.A.; Protti, M. (2000). "Analysis of seismic and acoustic observations at Arenal Volcano, Costa Rica, 1995–1997". Journal of Volcanology and Geothermal Research. 101 (1–2): 27–65. Bibcode:2000JVGR..101...27H. doi:10.1016/S0377-0273(00)00162-1.
  13. 1 2 Brown, K; Tryon, M; Deshon, H; Dorman, L; Schwartz, S (2005-09-30). "Correlated transient fluid pulsing and seismic tremor in the Costa Rica subduction zone". Earth and Planetary Science Letters. 238 (1–2): 189–203. doi:10.1016/j.epsl.2005.06.055.
  14. ↑ Malservisi, Rocco; Schwartz, Susan Y.; Voss, Nicholas; Protti, Marino; Gonzalez, Victor; Dixon, Timothy H.; Jiang, Yan; Newman, Andy V.; Richardson, Jacob; Walter, Jacob I.; Voyenko, Denis (2015). "Multiscale postseismic behavior on a megathrust: The 2012 Nicoya earthquake, Costa Rica". Geochemistry, Geophysics, Geosystems. 16 (6): 1848–1864. Bibcode:2015GGG....16.1848M. doi:10.1002/2015GC005794. ISSN   1525-2027. S2CID   54812854.
  15. ↑ Audet, Pascal; Schwartz, Susan Y. (2013). "Hydrologic control of forearc strength and seismicity in the Costa Rican subduction zone". Nature Geoscience. 6 (10): 852–855. Bibcode:2013NatGe...6..852A. doi:10.1038/ngeo1927. ISSN   1752-0894.
  16. ↑ Schwartz, Susan Y.; Lay, Thorne; Ruff, Larry J. (1989). "Source process of the great 1971 Solomon Islands doublet". Physics of the Earth and Planetary Interiors. 56 (3–4): 294–310. Bibcode:1989PEPI...56..294S. doi:10.1016/0031-9201(89)90164-7. hdl: 2027.42/27784 .
  17. ↑ Zhang, Zhi; Schwartz, Susan Y. (1994). "Seismic anisotropy in the shallow crust of the Loma Prieta segment of the San Andreas Fault System". Journal of Geophysical Research: Solid Earth. 99 (B5): 9651–9661. Bibcode:1994JGR....99.9651Z. doi:10.1029/94JB00241. ISSN   2156-2202.
  18. ↑ Schwartz, S. Y.; Orange, D. L.; Anderson, R. S. (1990). "Complex fault interactions in a restraining bend on the San Andreas Fault, southern Santa Cruz Mountains, California". Geophysical Research Letters. 17 (8): 1207–1210. Bibcode:1990GeoRL..17.1207S. doi:10.1029/GL017i008p01207. ISSN   1944-8007.
  19. ↑ "Loma Prieta Earthquake — Collective Museum". www.iascollectivemuseum.com. Retrieved 2021-09-07.
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