Sergio Eduardo Barrientos

• Ph.D.
• Managing Director at University of Chile

The aftershock distribution of the 2014 Mw 8.1 Iquique earthquake offshore northern Chile, identified from a long-term deployment of ocean bottom seismometers installed eight months after the mainshock, in conjunction with seismic reflection imaging, provides insights into the processes regulating the up-dip limit of coseismic rupture propagation....

WW ‐phase algorithm has been proven to be a reliable and robust method to calculate the centroid moment tensor (CMT) for moderate and large earthquakes. For global purposes, the WW ‐phase algorithm is operating in real time at the National Earthquake Information Center (NEIC), the Institut de Physique du Globe de Strasbourg (IPGS), and Pacific Tsun...

Seismic rupture of the shallow plate-boundary can result in large tsunamis with tragic socio-economic consequences, as exemplified by the 2011 Tohoku-Oki earthquake. To better understand the processes involved in shallow earthquake rupture in seismic gaps (where megathrust earthquakes are expected), and investigate the tsunami hazard, it is importa...

The importance of Global Navigation Satellite System (GNSS)-based earthquake early warning for modeling large earthquakes has been studied extensively over the past decade, and several such systems are currently under development. In the Pacific Northwest, we developed the Geodetic First Approximation of Size and Timing (G-FAST) GNSS-based earthqua...

In April 2017, a sequence of earthquakes offshore Valparaíso, Chile, raised concerns of a potential megathrust earthquake in the near future. The largest event in the 2017 sequence was a M6.9 on April 24th, seemingly co-located with the last great-sized earthquake in the region - a M8.0 in March 1985. The history of large earthquakes in this region...

Powerful subduction zone earthquakes rupture thousands of square kilometers along continental margins but at certain locations earthquake rupture terminates. To date detailed knowledge of the parameters that govern seismic rupture and aftershocks is still incomplete. On 16 September 2015 the Mw. 8.3 Illapel earthquake ruptured a 200 km long stretch...

W-phase moment tensor inversion has proven to be a reliable method for rapid characterization of large earthquakes. For global purposes it is used at the USGS (United States Geological Survey), PTWC (Pacific Tsunami Warning Center) and IPGS (Institut de Physique du Globe de Strasbourg). These implementations provide moment tensors within 30-60 min...

We demonstrate a flexible strategy for local tsunami warning that relies on regional geodetic and seismic stations. Through retrospective analysis of four recent tsunamigenic events in Japan and Chile, we show that rapid earthquake source information, provided by methodologies developed for earthquake early warning, can be used to generate timely e...

Early earthquake warning is a rapidly developing capability that has significant ramifications for many fields, including astronomical observatories. In this work, we describe the susceptibility of astronomical facilities to seismic events, including large telescopes as well as second-generation ground-based gravitational-wave interferometers. We d...

On 1 April 2014, Northern Chile was struck by a magnitude 8.1 earthquake following a protracted series of foreshocks. The Integrated Plate Boundary Observatory Chile monitored the entire sequence of events, providing unprecedented resolution of the build-up to the main event and its rupture evolution. Here we show that the Iquique earthquake broke...

The seismic gap theory identifies regions of elevated hazard based on a lack of recent seismicity in comparison with other portions of a fault. It has successfully explained past earthquakes (see, for example, ref. 2) and is useful for qualitatively describing where large earthquakes might occur. A large earthquake had been expected in the subducti...

After a long quiet period for earthquake activity with magnitude greater than 8.5, several great subduction megathrust earthquakes occurred during the past decade: Sumatra in 2004 and 2005, Chile in 2010, and Japan in 2011. Each of these events caused loss of life and damage to critical infrastructure on an enormous scale. And, in April, a Mw 8.2 e...

In 2007 a M7.7 earthquake occurred near the town of Tocopilla within the northern Chile seismic gap. Main shock slip, derived from coseismic surface deformation, was confined to the depth range between 30 and 55 km. We relocated ˜1100 events during six months before and one week after the main shock. Aftershock seismicity is first congruent to the...

On 2007 April 21, a M w = 6.2 earthquake shook the Aysén Fjord, Southern Chile in an unprecedented episode for this region characterized by low seismicity. The area is intersected by the Liquiñe-Ofqui Fault System (LOFS), a +1000-km-long strike-slip fault that absorbs part of the oblique convergence motion between Nazca and South America plates. To...

On 27 February 2010 the Mw 8.8 Maule earthquake in Central Chile ruptured a seismic gap where significant strain had accumulated since 1835. The postseismic phase was monitored by a network of temporary seismic stations (IMAD) and GPS stations along and around the whole rupture zone. Here, we examine the relation between the spatial-temporal proper...

Abstract On 27 February 2010 the Mw 8.8 Maule earthquake in Central Chile ruptured a seismic gap where significant strain had accumulated since 1835. Shortly after the mainshock a dense network of temporary seismic stations was installed along the whole rupture zone in order to capture the aftershock activity. Here, we present the aftershock distr...

On 27 February 2010 the M-w 8.8 Maule earthquake in Central Chile ruptured a seismic gap where significant strain had accumulated since 1835. Shortly after the mainshock a dense network of temporary seismic stations was installed along the whole rupture zone in order to capture the aftershock activity. Here, we present the aftershock distribution a...

On 27 February 2010 the Mw 8.8 Maule earthquake in Central Chile ruptured a seismic gap where significant strain had accumulated since 1835. Shortly after the mainshock a dense network of temporary seismic landstations was installed along the whole rupture zone in order to capture the aftershock activity. We present the aftershock distribution and...

On 27 February, 2010 a magnitude Mw 8.8 earthquake occurred off the coast of Chile's Maule region some 100 km N of Concepción, causing substantial damage and loss of life on Chile's mainland and the Juan Fernandez archipelago. The majority of the 521 fatalities are attributed to the earthquake, while the tsunami accounts for 124 victims. Fortunatel...

The 2004 M=9.1 Sumatra, 2010 M=8.8 Maule, and 2011 M=9.0 Tohoku earthquakes provide an unprecedented aftershock record, in part because the mainshocks are so much larger than the M~4.5 global completeness magnitude. Because large aftershocks can be damaging if they are shallow or located near populated areas, they matter to seismic hazards assessme...

During July 2011, a Pan-American Advanced Studies Institute, "New Frontiers in Seismological Research: Sustainable Networks, Earthquake Source Parameters, and Earth Structure" was conducted in Quito Ecuador with participants from the US, Central, and South America, and the Caribbean at early stages in their scientific careers. This advanced studies...

On 27 February 2010, a magnitude M w = 8.8 earthquake occurred off the coast of Chile’s Maule region causing substantial damage and loss of life. Ancestral tsunami knowledge from the 1960 event combined with education and evacuation exercises prompted most coastal residents to spontaneously evacuate after the earthquake. Many of the tsunami victims...

Abstract Available from http://www.agu.org

Abstract: On February 27, 2010, a magnitude Mw = 8.8 earthquake occurred off the coast of Chile’s Maule region causing substantial damage and loss of life. Ancestral tsunami knowledge from the 1960 event combined with education and evacuation exercises prompted most coastal residents to spontaneously evacuate after the earthquake. Many of the tsuna...

Large earthquakes produce crustal deformation that can be quantified by geodetic measurements, allowing for the determination of the slip distribution on the fault. We used data from Global Positioning System (GPS) networks in Central Chile to infer the static deformation and the kinematics of the 2010 moment magnitude (M(w)) 8.8 Maule megathrust e...

Static offsets produced by the February 27, 2010 Mw = 8.8 Maule, Chile earthquake as measured by GPS and InSAR constrain coseismic slip along a section of the Andean megathrust of dimensions 650 km (in length) x 180 km (in width). GPS data have been collected from both campaign and continuous sites sampling both the near-field and far field. ALOS/P...

A seismic swarm of more than 7200 earthquakes occurred in Aysen Fjord, southern Chile, from January to June 2007. It started suddenly on 23 January 2007 with an earthquake of magnitude Mw=5.3, followed by five earthquakes with magnitudes increasing from Mw=5.2 to 6.2 within three months. Two large earthquakes of magnitudes Mw=6.1 and 6.2 occurred o...

Unlike inertial sensors, GPS should reliably record both the dynamic (far-field) and static (near-field) displacements because of earthquakes. In 2002, high-rate (1-Hz and higher) GPS was first used to measure seismic waves from a large earthquake (M7.9 Denali); but nearly all the stations were in the far field. In 2004, the dense GPS network (GEON...

The Mw=8.8 Maule earthquake off the coast of Chile on February 27, 2010 is the 5th largest megathrust earthquake ever to be recorded and the 2nd largest to be recorded by modern digital seismic networks. Immediately following the Maule earthquake, teams of seismologists from Germany, France, the UK, and the US, working with seismologists in Chile,...

On 27 February 2010 a magnitude 8.8 earthquake occurred along the subduction zone in central Chile, rupturing a 350 km long section of the dipping fault interface. The southern part ruptured previously in 1835 during the M 8.5 Concepcion earthquake and the northern part ruptured in 1906 during the Mw 8.5 Valparaiso event. Immediately after the eart...

We find that the 22 May 1960 Mw=9.5 Chile earthquake increased the Coulomb stress at the future 2010 epicenter by 0.5 bar, an. Further, most aftershocks of both the 1960 M=9.5 and 27 February 2010 M=8.8 earthquakes locate at sites brought 10 or more bars closer to Coulomb failure on the megathrust surface. The 11 March 2010 Mw=6.9 ``Libertador O'Hi...

The largest recorded earthquakes have all taken place along subduction margins (e.g. Chile, 1960; Andaman-Sumatra, 2004; Chile, 2010). A better understanding of the stress distribution involved in these tectonic environments could lead to better prediction of the occurrence and maximum possible magnitudes of earthquakes at given segments of a subdu...

The February 2010 Mw 8.8 Chile earthquake ruptured a 450 km-long portion of the Nazca-South America subduction zone. The southern part of this section last ruptured in the 1835 magnitude 8.5 Concepcion event and the northernmost part in the 1906 Mw 8.5 Valparaiso earthquake. The 2010 rupture was also adjacent to the northern extent of the Mw 9.5 ea...

In November 2007 a M7.7 earthquake occurred near the coastal town of Tocopilla in the southern part of a presumed seismic gap extending some 500 km along the northern Chile subduction zone. This major segment last broke in a magnitude ≧8.5 earthquake in 1877. Assuming a complete lock of the interface, it has accumulated more than 8 m of slip def...

An AGU Chapman Conference commemorated the fiftieth anniversary of the 1960 M 9.5 Chile earthquake. Participants reexamined this earthquake, the largest ever recorded instrumentally, and compared it with Chile's February 2010 M 8.8 earthquake. They also addressed the giant earthquake potential of subduction zones worldwide and strategies for reduci...

El terremoto que afectó la zona centro-sur de Chile el 27 de Febrero de 2010 a las 03:34 (hora local) se originó en la zona de contacto entre las placas de Nazca y Sudamérica. La zona de ruptura se extiende por cerca de 450 km a lo largo de la costa frente a la región comprendida entre la Península de Arauco por el sur (37,8°S) y un poco al norte d...

The Mw 7.7 2007 November 14 earthquake had an epicentre located close to the city of Tocopilla, at the southern end of a known seismic gap in North Chile. Through modelling of Global Positioning System (GPS) and radar interferometry (InSAR) data, we show that this event ruptured the deeper part of the seismogenic interface (30-50 km) and did not re...

Installation of observatories in northern Chile started in 2006 in a close cooperation of the Universidad de Chile (Santiago), the Universidad Catolica del Norte (Antofagasta), the IPGP (Paris), and the GFZ Potsdam. Currently we operate 15 modern seismological stations equipped with STS-2 broadband seismometers. One GEOFON station operated since 20...

The oceanic Nazca plate subducts beneath the continental South American plate by recurrent rupture of large segments of its interface. The resulting earthquakes are among the largest and most frequent on Earth. Along the Chilean and southern Peruvian margin, all sizeable segments have ruptured at least once in the past 150 years for which there exi...

On April 21 2007 a magnitude 6.2 (Mw) earthquake took place near Aysen Fiord in southern Chile (45.37S, 73.02W) . This earthquake triggered large landslides and rockfalls on the abrupt topography of the northern and southern flanks of the Fiord. Upon striking the water, these landslides and rockfalls produced a major tsunami that significantly affe...

Installation of observatories in northern Chile started in 2006 in a close cooperation of the Universidad de Chile (Santiago), the Universidad Catolica del Norte (Antofagasta), the IPGP (Paris), and the GFZ Potsdam. Currently we operate 16 modern seismological stations equipped with STS-2 broadband seismometers. All seismic stations are located in...

To study crustal deformation at converging plate margins the Caltech Tectonics Observatory (CTO), together with partner institutions in the host countries, operates continuously observing GPS stations in the central Andes (northern Chile and southern Peru) and in Nepal. The currently 20-site Andes network was established in 2005 with 7 stations. Ef...

The Concepción–Constitución area [35–37°S] in South Central Chile is very likely a mature seismic gap, since no large subduction earthquake has occurred there since 1835. Three campaigns of global positioning system (GPS) measurements were carried out in this area in 1996, 1999 and 2002. We observed a network of about 40 sites, including two east–w...

The 4 September 1958 earthquake has been the largest event recorded at shallow depths in the western flank of the Andes on Chilean territory. New estimates of fault orientation, depth and size have been carried out using modern techniques of body-wave modeling. Two possible fault planes solutions with right-lateral displacement on an east-west faul...

Fast convergence between the oceanic Nazca and the continental South American plate is accommodated by recurrent rupture of large segments of the two plates' interface. The resulting earthquakes are among the largest and, for their sizes, most frequent on Earth. Along the Chilean and southern Peruvian margin, all segments have ruptured at least onc...

The November 2007 Tocopilla (Mw 7.7) earthquake occurred in the seismic gap of North Chile, a region where there has been no major thrust event in the last 130 years. A network of continuous GPS stations operated by IPGP, Caltech, DGF and IRD measured the coseismic displacement associated with this earthquake, as well as the subsequent post seismic...

Two large earthquakes took place in the later part of the XIX century in southern Peru and northern Chile, these are the August 13, 1868, and the May 9, 1877 (local time), events. Their estimated magnitudes are of the order of 9 rupturing contiguous segments of nearly 500 km each. Both of them accommodated the convergence between Nazca and South Am...

The CANTO (Central ANdean Tectonic Observatory) geodetic network captured the November 15 Tocopilla earthquake. Using GAMIT/TRACK software we compute 3-component 5Hz time series of station displacement to investigate coseismic and postseismic kinematics. We present spectral characteristics of the recorded coseismic waveforms and compare them to tho...

It has been almost two decades now that GPS has been used to measure plate tectonics and quantify plate deformation. In South America, the debate rapidly focused on the motion of the Nazca plate relative to the South America plate. Space geodesy allows to compare plate motions averaged over a few years to plate motion averaged over several million...

The 14 November 2007 earthquake that severely affected the city of Tocopilla, to a lesser extent, the city of Mejillones, can be characterized by two main patches of energy release -separated by a distance of the order of 65 km - along the interface between the Nazca and South American plates. Maximum vertical and horizontal accelerations reached v...

The Aysen seismic swarm began on January 22, 2007, with a large number of events up to magnitud 6.2 during a period of several months. We recorded this sequence with 4 permanent GPS stations before the main event, and with 10 GPS stations afterwards. All the GPS observations were processed with Bernese GPS software version 5.0. Stations from the re...

A Mw 7.7 subduction earthquake occurred on November 14, 2007 in Tocopilla (northern Chile). This region (between 16.5°S and 23.5°S) had been identified as major seismic gap (~1000 km length) that had not ruptured since the occurrence of the South Peru (Mw = 9.1, 16 August 1868) and the Iquique (Mw = 9.0, 10 May 1877) megathrust earthquakes. This ga...

After the November 14, 2007 Tocopilla earthquake in northern Chile, a local network of 20 short period seismic stations, 5 strong motion instruments, 6 GPS stations and 3 extensometers has been installed in the fault plane area between Tocopilla and Antofagasta by the German Task Force for earthquakes (GFZ Potsdam). The hydrogeology group of the TF...

A large Mw 7.7 earthquake took place in the Northern Chile subduction zone severely affecting the cities of Tocopilla, Maria Elena, Quillagua and Mejillones . The earthquake was very well recorded by many broadband stations at teleseismic distances and by more than 10 three-component accelerographs in the near field, four of them right above the ru...

Material inhomogeneities or geometrical irregularities are suggested to act as seismogenic structures which can influence rupture nucleation, propagation, and termination of large earthquakes. To evidence such a behaviour, a direct link between tectonic and/or geological conditions and the areas of focused co-seismic moment release or slip on a rup...

The new National Seismic Network of Chile, sponsored by the Government and executed by the Departments of Geophysics and Civil Engineering of the University of Chile, will consist of 65 broadband stations, sampled at 50 sps, colocated with more than 200 strong ground motion sensors sampled at 200 sps as well as 140 GPS instruments sampled at 1 sps....

Several efforts in Chile are being conducted in relation to geophysical monitoring with the objective of disaster mitigation. A long and permanent monitoring effort along the country has been the continuous effort resulting in the recognition and delineation of new seismogenic sources. Here we report on the seismo-volcanic crisis that is currently...

A total of 166 observations of sea-level change, 130 measurements of elevation difference, and 16 determinations of horizontal strain provide an excellent view of the (quasi-)static source process of the earthquake. These surface deformation data were employed in classical uniform slip fault models as well as more recently developed models that all...

The International Monitoring System (IMS) of the Preparatory Commission of the Comprehensive Nuclear Test- Ban Treaty Organization (CTBTO) has built a sixteen element broadband seismic array in southwestern Niger near the town of Torodi. This is the first array to be built in West Africa. The array has a diameter of 6 km (three rings with a central...

Abstract Indications of transient crustal displacement associated with the 3 March 1985, M, = 7.8, Central Chile earthquake are evidenced by various observational devices. Almost half a meter of coastal uplift at localities close to the epicentral region was detected by repeated leveling lines. A tide gauge at Valparaiso revealed minor coseismic co...

The behaviour of a seismic fault in Chile seemed to confound predictions of how often giant earthquakes should recur. Examination of a 2,000-year record of tsunami deposits in the region clarifies matters.

Both the genesis and rates of activity of shallow intraplate seismic activity in central Chile are poorly understood, mainly because of the lack of association of seismicity with recognizable fault features at the surface and a poor record of seismic activity. The goal of this work is to detail the characteristics of seismicity that takes place in...

Since the establishment of the Provisional Technical Secretariat (PTS) of the Comprehensive Nuclear-Test-Ban Treaty (CTBT) Organization, a vigorous seismic site survey program has been carried out to identify locations as necessary for International Monitoring System (IMS) primary and auxiliary seismic stations listed in Annex 1 to the Protocol to...

We study the possible seismic gap in the Concepción–Constitución region of south-central Chile and the nature of the M=7.8 earthquake of January 1939. From 1 March to 31 May 1996 a seismic network of 26 short period digital instruments was deployed in this area. We located 379 hypocenters with rms travel time residuals of less than 0.50 s using an...

Two campaigns of Global Positioning System (GPS) measurements were carried out in the Concepción-Constitución area of Chile in 1996 and 1999. It is very likely that this area is a mature seismic gap, since no subduction earthquake has occurred there since 1835. In 1996, 32 sites were occupied in the range 35°S-37°S, between the Pacific coast of Chi...

Closure of the Pacific Ocean basin by the convergence of its surrounding plates, some of which have deep continental roots, implies that there is net mass flux out of the mantle under the Pacific. Here we report on a shear-wave splitting study designed to test the prediction that there should be flow around its southern margin. Our results show no...

In order to study both the interplate seismic loading cycle and the distribution of intraplate deformation of the Andes, a 215 site GPS network covering Chile and the western part of Argentina was selected, monumented and observed in 1993 and 1994. A dense part of the network in northern Chile and northwest Argentina, comprising some 70 sites, was...

We have analyzed four large to great historic earthquakes that occurred along the central Chile subduction zone from north to south on November 11, 1922 (M-s = 8.3), April, 1943 (M-s = 7.9), December 1, 1928 (M-s = 8.0) and January 25, 1939 (M-s = 7.8). Waveform modeling and P-wave first motions indicate that the 1922, 1928 and 1943 earthquakes are...

Coralline algae that may be predominant in the upper part of the infralittoral zone along rocky shorelines proved to be a useful indicator of rapid coastal uplift. As these encrusting algae cannot survive desiccation, even for short periods at low tide, they can provide estimates of positive vertical motions like those which may accompany seismic e...

A strong (Mw = 8.1) subduction earthquake occurred on July 30, 1995 in Antofagasta (northern Chile). This is one of the largest events during this century in the region. It ruptured the southernmost portion of a seismic gap between 18°S and 25°S. In 1992 we had used GPS to survey a network with about 50 benchmarks covering a region nearly 500 km lo...

Les changements d'élévation verticale qui ont été observées lors des trois grands tremblements de terre au Chili (1960, 1985 et 1995), sont utilisés pour déterminer l'extension de la zone sismogénique en profondeur. L'interpolation des axes de changement d'élévation nul observés pour ces trois grands séismes en fonction de leur distance à la fosse,...

Plusieurs nids de sismicité superficielle intraplaque (0-20 km de profondeur), sans relation connue avec les failles en surface, sont détectés depuis déjà 10 ans par les réseaux sismologiques, sur le flanc occidental des Andes dans la région centrale du Chili. La localisation de ces séismes est faite à partir d'un modèle de vitesses déduit d'un pro...

L'étude néotectonique des Andes du Chili central (dépression centrale et zone de faille Liquine-Ofqui) montre un champ de contrainte avec s(indice Hmax)(s1) plus ou moins EW au Miocène supérieur-Pliocène (entre 10 et 3 Ma), sub-parallèle à la direction de convergence des plaques Nazca et Amérique du Sud. Le régime tectonique est transpressif à comp...

La géométrie et la cinématique des zones de cisaillement crustales pré-Eocène (?) à Pliocène, l'agencement régional des dikes basiques, la distribution spatiale des centres volcaniques holocènes, et les quelques séismes crustaux intra-arc, suggèrent que l'arc magmatique des Andes chiliennes du sud a subi des déformations transtensives à transpressi...

Repeated leveling lines evidenced almost half a meter of uplift at coastal localities nearby the epicentral region of the March 3, 1985, Ms=7.8, Central Chile earthquake. A tide gauge at Valparaiso and two limnigraphs, 27 km apart, situated at the extremes of Rapel Lake, to the south of the leveling line, have been recording continuously sea level...

Forty-eight hours after the occurrence of the May 22, 1960 (M W =9.5) Chile earthquake, Puyehue volcano initiated its eruptive activity. The closeness in space and time of both phenomena provides us with a unique opportunity to examine the possible causal relationship between the sudden strain change and the mechanism of the eruption. From the sli...

The time and space distribution of rupture segments along south-central Chile suggest the high probability of of a large magnitude earthquake occurring in the proposed seismic gap (34.3°–37.2°S) located between the 1960 and 1985 rupture regions. Three lines of evidence support the occurrence of a magnitude 8+ event within the next couple of decades...

Growth of Durmid Hill, a low elongate topographic dome at the southeast of the San Andreas fault, has been related in the past to transpression along the San Andreas fault (Babcock, 1974; Buergmann, 1991). This paper analyzes the Durmid Hill's doming history between September 1985 and December 1991, obtained from leveling data collected on the 2.27...

More than 1600 earthquakes were recorded, in a four-month period, on portable seismographic stations installed in the Lonquimay area, immediately after the initiation of the volcanic eruption of December 25, 1988. Hypocentral parameters were calculated on a subset of 150 events showing clear arrivals. Seismic activity was restricted to a north-sout...

Leveling surveys conducted in Nepal over the past 15 years indicate interseismic local uplift and depression of surface rocks with wavelengths of 30-50 km. Localized uplift of 4 +/-1 mm/yr in the Greater Himalaya is geographically coincident with the north-west, south-east trend of the high Himalaya peaks and near an inferred zone of increased dip...

Tide gage records at Puerto Montt, referenced to a mareograph in Talcahuano, indicate a large (at least 75 cm) postseismic uplift of the region following the 1960 MW=9.5 event. Field observations carried out in 1989 at the same locations of previous measurements in 1968 are consistent with tide gage records. The postseismic elevation changes are mo...

Geodetic elevation changes record the deformation associated with the Ms = 7.8, March 3, 1985, Central Chile earthquake. By summing elemental point sources in a half-space and employing a gradient technique with positivity constraints, we resolve the slip distribution on the dislocation surface. Most of the fault slip is concentrated on two patches...

This paper develops an inversion technique for static surface displacements associated with shallow faulting and applies the method to geodetic observations of the Borah Peak, Idaho, earthquake (M0=7.3) of October 28, 1983. This technique improves upon classical, uniform slip planar (USP) models by admitting earthquake faults which are curved and c...

Geodetic elevation changes record the broad-scale deformation associated with the M=7.0 October 28, 1983, Borah Peak, Idaho, earthquake on the Lost River fault. The crest of the Lost River Range rose 0.2 m, and adjacent Thousand Springs Valley subsided 1.0 m, in relation to reference points 45 km from the main shock epicenter. The deformation was m...

Thesis (Ph. D.)--University of California, Santa Cruz, 1987. Includes bibliographical references (leaves 96-97). Microfiche. s