Robert W King

• massachusetts institute of techonlogy

Geodetic observations in the Turkana Depression of southern Ethiopia and northern Kenya constrain the kinematic relay of extension from a single rift in Ethiopia to parallel rifts in Kenya and Uganda. Global Position System stations in the region record approximately 4.7 mm/year of total eastward extension, consistent with the ITRF14 Euler pole for...

We present and interpret newly determined site motions derived from GPS observations made from 2008 through 2016 in the Republic of Georgia, which constrain the rate and locus of active shortening in the Lesser–Greater Caucasus continental collision zone. Observation sites are located along two ∼160 km-long profiles crossing the Lesser–Greater Cauc...

The Geodesy Advancing Geosciences and EarthScope (GAGE) Facility Global Positioning System (GPS) Data Analysis Centers produce position times series, velocities and other parameters for approximately two thousand continuously operating GPS receivers spanning a quadrant of Earth's surface encompassing the high Arctic, North America and Caribbean. Th...

Geodetic, geologic and paleomagnetic data reveal that Oregon (western USA) rotates clockwise at 0.3 to 1.0 °/Ma (relative to North America) about an axis near the Idaho-Oregon-Washington border, while northeast Washington is relatively fixed. This rotation has been going on for at least 15 Ma. The Yakima fold and thrust belt (YFTB) forms the bounda...

Measurements from GPS sites spanning the Ethiopian Highlands, Main Ethiopian Rift, and Somali Platform in Ethiopia and Eritrea show that present-day finite strain rates throughout NE Africa can be approximated at the continent scale by opening on the MER. Most sites in the Ethiopian Highlands are consistent with the motion of the Nubian plate at th...

Thank you, Matt. I am honored to receive an award named for someone who has not only been an inspiration to me throughout my career but whose critical role in the formation of the International GPS (now GNSS) Service (IGS) has made possible both my own research and my ability to assist others in the art of GPS data analysis.

During the past century, a series of predominantly westward migrating M > 7 earthquakes broke an ~1000 km section of the North Anatolian Fault (NAF). The only major remaining “seismic gap” along the fault is under the Sea of Marmara (Main Marmara fault [MMF]). We use 20 years of GPS observations to estimate strain accumulation on fault segments in...

[1] Surface velocities derived from GPS observations from 1993 to 2011 at several hundred sites across the deforming northwestern United States are used to further elucidate the region's active tectonics. The new velocities reveal that the clockwise rotations, relative to North America, seen in Oregon and western Washington from earlier GPS observa...

We estimate horizontal velocities for 405 sites using Global Positioning System (GPS) phase data collected from 1994 to 2010 within the Northern Basin and Range Province, U.S.A. The velocities reveal a slowly-deforming region within the Snake River Plain in Idaho and Owyhee-Oregon Plateau in Oregon separated from the actively extending adjacent Bas...

The potential for large, shallow earthquakes and their associated seismic hazard in the eastern Caucasus, an area of dense population and sensitive industrial infrastructure, remains speculative based on historical precedent and current geologic and seismologic observations. Here we present updated and expanded results from a GPS network between th...

The Pyrenees mountain belt, which separates the Iberian Peninsula from the rest of the European continent, is part of the Alpine–Himalayan orogenic belt, formed as a result of a collision between the African and Eurasian Plates. Although the instrumental seismicity in the Pyrenees is moderate, in the past centuries a number of destructive earthquak...

We evaluate horizontal Global Positioning System (GPS) velocities together with geologic, volcanic, and seismic data to interpret extension, shear, and contraction within the Snake River Plain and the Northern Basin and Range Province, U.S.A. We estimate horizontal surface velocities using GPS data collected at 385 sites from 1994 to 2009 and prese...

GPS observations along three profiles across the Ethiopian Rift and Afar triple junction record differences in the length scale over which extension is accommodated. In the Afar region, where the mantle lithosphere is nearly or entirely absent, measurable extension occurs over ˜175 km; in the northern Ethiopian Rift, where the mantle lithosphere is...

The Absheron Peninsula lies at the junction of the ˜ E-W striking, north-verging, intra-continental Main Caucasus Thrust Fault (MCTF) and the Central Caspian Seismic Zone (CCSZ). The MCTF accommodates shortening between the Lesser and Greater Caucasus Mountains, and the CCSZ is thought to reflect the early stages of subduction of the southern Caspi...

The Yakima fold-thrust belt (YFTB; also known as Yakima Fold Belt), forming the distinct geomorphology of northernmost Oregon and south-central Washington, is one of the few actively deforming fold and thrust belts in the conterminous United States. Although controversial, currently available data suggest that the YFTB is "thick-skinned", i.e., its...

Geologic studies indicate that northwestern Oregon contains a system of faults, notably the Portland Hills Fault and Gales Creek Fault, though uncertainty exists regarding their rates of motion. On the larger scale of the northwestern United States, previous work has indicated relative motions as crustal block rotations whose axes of rotation gener...

Non-gravitational forces such as solar radiation pressure, earth radiation pressure, antenna thrust and thermal re-radiation are relatively small contributors to the overall GPS satellite orbital force budget. However, if neglected, these small non-gravitationally induced accelerations produce significant errors in satellite positions and velocitie...

The use of so-called 'block models' to represent the deformation of the Earth's surface has become widespread, in particular to explain the ever-increasing number of GPS velocities that are becoming available. The blocks represent portions of the lithosphere that are separated by faults and extend from the surface to a depth where the faults become...

To determine crustal motions in and around southern California, we have processed and combined trilateration data collected from 1970 to 1992, VLBI data from 1979 to 1992, and GPS data from 1986 to 2004: a long temporal coverage required in part by the occurrence of several large earthquakes in this region. From a series of solutions for station po...

We use velocities from 65 continuous stations and 31 survey-mode GPS sites as well as kinematic modeling to investigate present day deformation along the Africa–Iberia plate boundary zone in the western Mediterranean region. The GPS velocity field shows southwestward motion of the central part of the Rif Mountains in northern Morocco with respect t...

As an aid to survey design, we used data acquired from three European continuous GPS networks to test the precision of position estimates from static observations as a function of the length of the observing session and the number and distribution of reference stations. Our criterion was the weighted RMS of estimates over 31days with respect to coo...

Surface velocities derived from GPS observations have allowed high resolution views of the active deformation and rotation of the Cascadia forearc and backarc as well as elastic strain accumulation arising from subduction fault locking. We present an update of the Pacific Northwest GPS velocity field presented earlier by McCaffrey et al. (Geophys....

The active Yellowstone volcanic system is characterized by episodic deformation. Recent geodetic measurements revealed four major episodes of caldera inflation and deflation: 1992-1995, 1996-2000, 2000-2004, and 2004-2010. The Yellowstone caldera floor subsided at varying rates (about 0.7-3 cm/yr) during 1992-2004 and uplifted at approximately 2-7...

We use data from 31 survey-mode Global Positioning System (GPS) measurements in Morocco from 1999 to 2006 (Fadil et al. 2006) and 65 continuous GPS stations extending from Morocco to south of Spain to derive an improved velocity field for the western Mediterranean. Velocities from 42 new stations confirm the earlier results of Fadil et al. showing...

Crustal deformation in the Northern Basin and Range and Snake River Plain results from extension overprinted by volcanism associated with the Yellowstone Hotspot. The Snake River Plain is a seismically quiet, low-relief physiographic feature that extends from eastern Oregon through southern Idaho and into northwestern Wyoming. The Northern Basin an...

Three Quaternary NW-trending normal faults (Lost River, Lemhi, and Beaverhead) within the Centennial Tectonic Belt (CTB) appear to terminate at the northwestern boundary of the Eastern Snake River Plain (ESRP). The northern and central segments of the three normal faults are seismically active, but their activity decreases southward toward the ESRP...

The northwest boundary of the Snake River Plain (SRP) is a transition from range-bounding normal faults in the Centennial tectonic belt (CTB) to the topographically low and volcanic-dominated province of the SRP. Within the CTB, the northern and central segments of three prominent NW-trending normal faults are seismically active, but their activity...

The northwest boundary of the Snake River Plain (SRP) is a transition from range-bounding normal faults in the Centennial tectonic belt (CTB) to the topographically low and volcanic-dominated province of the SRP. Within the CTB, the northern and central segments of three prominent NW-trending normal faults are seismically active, but their activity...

The South Balkan extensional system consists of normal faults and associated sedimentary basins within southern Bulgaria, Macedonia, eastern Albania, northern Greece, and northwestern Turkey. Extensional tectonism began during the final convergence across the Vardar, Intra-Pontide, and Izmir-Ankara suture zones, where oceanic regions closed between...

New horizontal GPS velocities along with earthquakes, faults, and volcanic features are used to assess how strain is accommodated in the Northern Basin and Range Province. We used GPS phase data collected from 1994 to 2007 to estimate horizontal velocities for 132 stations within the Snake River Plain (SRP) and surrounding basin and range. These ve...

On 12 May 2008, a magnitude 7.9 earthquake ruptured the Longmen Shan margin of the eastern Tibetan plateau. This event occurred within the context of long-term uplift and eastward enlargement of the plateau. The area has numerous geological features not typical of active convergent mountain belts, including the presence of a steep mountain front (>...

The east of the Qinghai-Tibet plateau and adjacent areas are the most typical mainland lithosphere distortion zones. According to GPS measurement, the velocity field on the Eurasia reference framework was obtained. And the velocity vector about the block motion and rotation was computed by least squares fitting under the hypotheses of rigid mass. G...

The present day tectonic pattern of the Balkan Peninsula has evolved from three major periods of mainly extensional tectonism: (i) Paleogene extension that is difficult to characterize because its relation to the closing of the Vardar Ocean remains uncertain; (ii) Early to Late Miocene extension related to rollback at the Hellenic subduction zone;...

We present results from GPS observations in Bulgaria, Macedonia, and Albania, which describe a crustal velocity field for the south Balkan region with an accuracy of better than 1 mm/year. Our results show an overall southward motion of the region with respect to Eurasia at a rate of 3–4 mm/year. Much of the area behaves as a single tectonic unit w...

Previous investigators have proposed that extension within the eastern Snake River Plain (ESRP) is accommodated by intrusion of dikes at a rate similar to the rate of extension in the surrounding Basin and Range. This hypothesis is primarily based on the lack of strike-slip offset along the northwest physiographic boundary of the ESRP, the lack of...

Ongoing plate convergence between India and Eurasia provides a natural laboratory for studying the dynamics of continental collision, a first-order process in the evolution of continents, regional climate, and natural hazards. In southeastern Tibet, the fast directions of seismic anisotropy determined using shear-wave splitting analysis correlate w...

We interpret Global Positioning System (GPS) measurements in the northwestern United States and adjacent parts of western Canada to describe relative motions of crustal blocks, locking on faults and permanent deformation associated with convergence between the Juan de Fuca and North American plates. To estimate angular velocities of the oceanic Jua...

The Plate Boundary Observatory is being installed along the Pacific-North America plate boundary and when complete will add 875 new GPS sites and incorporate 209 existing GPS sites into the network. The GPS phase data from all these sites and an additional 40 sites to tie to the North America plate are analyzed by PBO analysis centers (ACs) at the...

GPS velocities, earthquakes, faults, and volcanic features are used to evaluate contemporary deformation within the Snake River Plain (SRP) and surrounding northern Basin and Range Province. The SRP is a prominent low- relief physiographic feature that extends from eastern Oregon through southern Idaho and into northwestern Wyoming, USA. The Easter...

Ongoing plate convergence between India and Eurasia provides a natural laboratory for studying the dynamics of continental collision, a first-order process in the evolution of continents, regional climate, and natural hazards. In southeastern Tibet, the fast directions of seismic anisotropy determined using shear-wave splitting analysis correlate w...

The first GPS site in the Plate Boundary Observatory (PBO) component of the National Science Foundation's Earthscope project was installed in January 2004. As of September 2006, 411 PBO GPS sites have been installed with 50 of these sites located on or near active volcanoes around the plate boundary. In addition to these new sites, 209 pre-existing...

GPS measurements in the northwestern US and adjacent parts of Canada describe the relative motions of crustal blocks, the interseismic friction on faults, and the permanent deformation associated with convergence between the Juan de Fuca and North American plates. To estimate angular velocities of the oceanic Juan de Fuca and Explorer plates and se...

1] Independent Okhotsk and Amurian microplate motions are tested using velocities from 123 GPS sites (80 from within the proposed OKH and AMU plate boundaries) used to constrain the plate kinematics of northeast Asia. A block modeling approach is used to incorporate both rigid block rotation and near-boundary elastic strain accumulation effects in...

GPS results from 25 stations in Macedonia measured in 1996 and 2000 show that Macedonia moves SSE relative to Eurasia essentially as a single crustal piece along with parts of westernmost Bulgaria. Geological studies show active N–S normal faults and two NNW-striking right-lateral faults in western Macedonia, and NW-trending left-lateral faults SE...

Global Positioning System (GPS) data acquired between 1996 and 2004 and fault plane solutions for four seismic zones are analyzed to obtain the velocity and strain rate fields for western Bulgaria. The GPS derived velocities suggest that southwestern Bulgaria moves to the S to SSE at a rate of ∼1 mm/year with respect to northern Bulgaria and southe...

The Plate Boundary Observatory GPS data analysis centers (ACs) at the Berkeley Seismological Laboratory (BSL) and Central Washington University (CWU), and the analysis center coordinator (ACC) at the Massachusetts Institute of Technology began establishing the GPS processing centers on April 1, 2005. The PBO GPS data analyses will be operational on...

The possibility of Okhotsk plate motion independent of the North American plate and Amurian plate motion independent of Eurasia were tested rigorously using velocities from 106 GPS sites (58 from within the proposed Okhotsk and Amurian plate boundaries) in order to constrain the plate kinematics of East Asia. A block modeling approach was used to i...

Seismological (Holt et. al. 1996), geodetic (King et. al. 1996, Chen et. al. 2000) and geological (Wang et. al. 1995, Wang and Burchfiel 2002) studies have shown that upper crustal material north and east of the eastern Himalayan syntaxis rotates clockwise about the syntaxis, with the Xianshuihe fault accommodating most of this motion. Within the z...

GPS measurements indicate that much of the deformation in the Pacific Northwest occurs from the clockwise rotation of the "Oregon block" about a rotation pole located near the eastern end of the Oregon-Washington boundary. Strain rates of less than 1 nanostrain per year in Oregon (corrected for strain due to subduction along the Pacific coast)estab...

The Kodiak Islands are located ∼120 to 250 km from the Alaska-Aleutian Trench and are within the southern extent of the 1964 Prince William Sound (Mw = 9.2) earthquake rupture and aftershock zone. Here we report new campaign GPS results (1993-2001) from northeastern Kodiak and reprocessed GPS results (1993-1997) from Southwestern Kodiak. The rate a...

The history and reasons for the use of geodesy in geophysics are reviewed, and the basic principles behind relative positioning using GPS are described. The success of this approach to the measurement of crustal deformation is evaluated. Specific examples of results relevant to tectonics are given along with an overview of work in progress.

[1] Interseismic GPS velocities in Sakhalin indicate that the island moves to the west at 3–4 mm/yr with respect to the Eurasian plate, which is about half of the relative Eurasia - North America plate convergence rate. GPS measurements across the central Sakhalin fault system provide evidence of compressive and strike-slip strain accumulation at a...

The degree of stick-slip coupling on the Cascadia subduction zone and the motions of the surrounding plates, large and small, are inferred by simultaneous inversion of GPS velocities, surface tilt rates, surface uplift rates, surface horizontal strain rates, spreading rates, slip vectors, and transform fault azimuths. Motion of the Pacific plate re...

Between 1991 and 2002 we have performed ten GPS surveys on the eastern Tibetan plateau and its margins. We have analyzed the observations from these surveys together with global GPS observations to estimate the motion and deformation of crustal blocks on scales of several hundred to thousands of kilometers. Viewed with respect to a Eurasian plate d...

We estimate present day slip rates on all of the major faults in southern California using block models fit to the geodetically determined interseismic velocities of the SCEC Crustal Motion Model (http://www.scec.org). The block model approach accounts for elastic strain accumulation due to motion on block-bounding faults and yields kinematically c...

The National Science Foundation supports the Incorporated Research Institutions for Seismology (IRIS) and the University NAVSTAR Consortium (UNAVCO) to provide the infrastructure needed for U.S. scientists to conduct seismological and Global Positioning System (GPS) measurements throughout the world. As part of IRIS and UNAVCO activities, data cent...

Through observation and studies of earthquake precursors, the paper set forth the facts and reasons why damaging earthquakes Ms>6.0 can be accurately predicted. Accord- ing to characteristics of earthquake precursors, the initiation, development, movement, transfer, and occurrence process of earthquakes, can be classified into several explicit, con...

Results from GPS network of 42 stations measured in 1996, 1997, 1998 and 2000 and our geological studies indicate that Bulgaria can be separated into four major velocity “domains”: an Eastern Domain that does not move relative to Eurasia, a North-central Domain that moves to the NE, a South-central Domain that moves to the SSE, and a Western Domain...

Over the past decade, rapid ground deformation has been measured over the Coso geothermal field in Eastern CA using InSAR and GPS. InSAR resolves changes in distance along the line-of-sight (LOS) to the satellite with high spatial coverage. In the Coso geothermal field the maximum LOS displacements are up to 35 mm/yr. The inclination of the LOS is...

The velocities of 16 stations extending from Svalbard Island in the north Atlantic to eastern Siberia define the Eurasian plate with a root-mean-square (rms) less than 1 mm/yr. Using these stations as a frame of reference, we have estimated velocities for 58 stations in east Asia from the Arctic to southern China and combined these with the results...

To measure current deformation in southern California, the Southern California Earthquake Center (SCEC) has been collecting and analyzing geodetic data from a wide range of sources, and providing the results in the form of station velocities. These crustal motion results can be used to study tectonic processes and relate crustal deformation to eart...

We use Global Positioning System (GPS) data from 1993–2000 to determine horizontal velocities of 65 stations in eastern California and western Nevada between 35° and 37° N. We relate the geodetic velocities to fault slip rates using a block model that enforces path integral constraints over geologic and geodetic time scales and that includes the ef...

Model inversions of displacements of continuously operating GPS stations in Kamchatka show that aseismic afterslip during 2 months following the Mw=7.8, 5 December, 1997 Kronotsky subduction earthquake released as much moment as the earthquake itself. The rapidly decaying transient slip on the subduction underthrust occurred near the downdip edge o...

To determine the present day kinematics of the major tectonic elements in Bulgaria, part of the northern extent of the Aegean extensional system, we established and surveyed a regional GPS network in 1996, 1997 and 1998. Based on our estimates of the velocities of 17 stations surveyed at least twice, we identify two areas of significant deformation...

The Black Sea occurs within the Anatolian sector of the Alpine-Himalayan orogenic system. In this region northward moving African and Arabian plates collide with Eurasian plate. From this collision the Anatolian block moves westward with a rotation pole located approximately north of Sinai peninsula. Tectonic styles and rates in the circum Black Se...

GPS observations in northeastern Asia, when combined with observations from the global network for the period 1992-1999, yield an angular rotation vector between Eurasia and North America consistent with and a factor of two more precise than estimates derived using GPS or VLBI data previously available from only western Eurasia. The new vector impl...

We present and interpret Global Positioning System (GPS) measurements of crustal motions for the period 1991-1998 for a network encompassing the eastern part of the Tibetan Plateau and its foreland. Relative to a Eurasian frame defined by minimizing the velocities of 16 GPS stations in Europe, central Asia, and Siberia, stations within all parts of...

We present and interpret Global Positioning System (GPS) measurements of crustal motions for the period 1991-1998 for a network encompassing the eastern part of the Tibetan Plateau and its foreland. Relative to a Eurasian frame defined by minimizing the velocities of 16 GPS stations in Europe, central Asia, and Siberia, stations within all parts of...

We present and interpret Global Positioning System (GPS) measurements of crustal motions for the period 1988-1997 at 189 sites extending east-west from the Caucasus mountains to the Adriatic Sea and north-south from the southern edge of the Eurasian plate to the northern edge of the African plate. Sites on the northern Arabian platform move 18+-2 m...

Through GPS carrier phases observation in southwestern China during 1991–1997, the velocity field within eastern Qinghai-Xizang (Tibet) and its neighbour regions has been established. The velocity of those sites in and west of Chuan-Dian block is mostly 5–10 mm · a™1 relative to the fiduciary station CHDU (Chengdu), and the motion in Chuan-Qing and...

The GPS velocity field of the Aegean Sea and western Anatolia is used to determine crustal deformation strain rates for the period 1988 to 1996. The zone from the Marmara Sea to the North Aegean Trough is associated with strong right-lateral shear motion, with maximum strain rates of 170 nstrain/a. In the northern Aegean Sea the extensional deviato...

We use the combined GPS velocity field of the eastern Mediterranean for the period 1988 to 1996 to determine crustal deformation strain rates in a region comprising the Hellenic arc, the Aegean Sea, and western Anatolia. We interpret the velocity field and determine the strain rate tensor by the spatial derivatives of the collocated motion vectors....

The rate and orientation of ongoing strain associated with subduction of the Pacific plate and the accretion of the Yakutat terrane to southern Alaska has been estimated at 13 sites from Global Positioning System measurements made in June 1993 and 1995. Along the Gulf of Alaska coast near Cape Yakataga, the average rate of deformation, relative to...

We discuss an approach for efficiently combining different types of geodetic data to estimate time-dependent motions of stations in a region of active deformation. The primary observations are analyzed separately to produce loosely constrained estimates of station positions and coordinate system parameters which are then combined with appropriate c...

Studies at the Southern California Earthquake Center (SCEC) are suggesting that postseismic deformation is significant and long lasting. This seems the case, at least, in a region whose dimension is comparable to the fault rupture length. Researchers at SCEC found strong spatial correlation between the high strain rates and the past large earthquak...

Field observations and satellite geodesy indicate that little crustal shortening has occurred along the central to southern margin of the eastern Tibetan plateau since about 4 million years ago. Instead, central eastern Tibet has been nearly stationary relative to southeastern China, southeastern Tibet has rotated clockwise without major crustal sh...

We present and interpret Global Positioning System (GPS) measurements of crustal motions for the period 1988-1994 at 54 sites extending east-west from the Caucasus mountains of southern Russia, Georgia, and Armenia to the Aegean coast of Turkey and north-south from the southern edge of the Eurasian plate (Pontus block) to the northern edge of the A...

Global Positioning System measurements performed over a 2 4 yr period confirm the Xianshuihe-Xiaojiang fault system as one of the primary active structures in southwest China. Stations southwest of these faults show southerly motions of 5 15 mm/yr relative to the western Sichuan basin, and stations in a 200 km geodetic network located northwest of...

The 17 January 1994 Northridge, California, earthquake significantly deformed the Earth's crust in the epicentral region. Displacements of 66 survey stations determined from Global Positioning System (GPS) observations collected before and after the earthquake show that individual stations were uplifted by up to 417 _ 5 mm and displaced horizontall...

Geophysicists are using the Global Positioning System (GPS), a highly precise satellite navigation system, to monitor the slow movements (cm/yr) of the crustal plates composing the Earth's surface and the deformations where such plates interact. We report the results of repeated GPS measurements in the complex zone of interaction between the Eurasi...

Recent geological and geodetic studies have suggested that the region surrounding Vandenberg Air Force Base, CA, is undergoing active crustal deformation, with important implications for both the geodetic stability and the seismogenic potential of the Western Test Range. In 1989, funding was received (AFOSR 89-0400) for the purchase of several GPS...

The inherent precision of the doubly differenced phase measurement and the low cost of instrumentation made GPS the space geodetic technique of choice for regional surveys as soon as the constellation reached acceptable geometry in the area of interest: 1985 in western North America, the early 1990's in most of the world. Instrument and site-relate...