James Jackson

• Northumbria University

This paper is concerned with the distribution of earthquakes, particularly their depths, with the temperature of the material in which they occur, and with the significance of both for the rheology and deformation of the continental lithosphere. Earthquakes on faults are generated by the sudden release of elastic energy that accumulates during slow...

The Tien Shan accommodates a significant portion of the India‐Eurasia N‐S convergence. In its northern part a zigzag pattern of mountain ranges bounds the western Ili Basin. The role of this basin in the overall shortening and the regional kinematics is not well understood. Geodetic data and instrumental seismicity are not sufficient to infer the r...

The relative motion between the South Caspian Basin (SCB) and its surroundings is accommodated by left-lateral fault systems in Iran, and the right-lateral Main Kopeh Dagh Fault (MKDF, aka Ashgabat Fault) in Turkmenistan. Determining the rates of slip on these faults is key for understanding the motion of the SCB. However, several different tectoni...

High-resolution elevation models, palaeoseismic trenching, and Quaternary dating demonstrate that the Kenchreai Fault in the eastern Gulf of Corinth (Greece) has ruptured in the Holocene. Along with the adjacent Pisia and Heraion Faults (which ruptured in 1981), our results indicate the presence of closely-spaced and parallel normal faults that are...

The relative motion between the South Caspian Basin (SCB) and its surroundings is accommodated by left-lateral fault systems in Iran, and the right-lateral Main Kopeh Dagh Fault (aka Ashgabat Fault) in Turkmenistan. Determining the rates of slip on these faults is key for understanding the motion of the SCB. However, several different tectonic mode...

Convergence in the eastern Mediterranean of oceanic Nubia with Anatolia and the Aegean is complex and poorly understood. Large volumes of sediment obscure the shallow structure of the subduction zone, and since much of the convergence is accommodated aseismically, there are limited earthquake data to constrain its kinematics. We present new source...

Seismological, GPS and historical data suggest that most of the 40 mm yr−1 convergence at the Hellenic Subduction Zone is accommodated through aseismic creep, with earthquakes of MW ≲ 7 rupturing isolated locked patches of the subduction interface. The size and location of these locked patches are poorly constrained despite their importance for ass...

The dominant uncertainties in assessing tsunami hazard in the Eastern Mediterranean are attached to the location of the sources. Reliable historical reports exist for five tsunamis associated with earthquakes at the Hellenic plate boundary, including two that caused widespread devastation. Because most of the relative motion across this boundary is...

Several large earthquakes in the Hellenic subduction zone have been documented in historical records from around the eastern Mediterranean, but the relative seismic quiescence of the region over the period of instrumental observation means that the exact locations of these earthquakes and their tectonic significance are not known. We present AMS ra...

Around one quarter (~10 mm/yr) of the India-Eurasia convergence is accommodated across the Tien Shan and Dzhungarian Ala-tau mountain ranges of eastern Kazakhstan. Essentially N-S shortening is distributed among a number of active faults in a wide area. E-W trending thrust faults and growing anticlines appear to accommodate the majority of shorteni...

[1] Unravelling the contributions of mainshock slip, aftershocks, aseismic afterslip and postseismic relaxation to the deformation observed in earthquake sequences heightens our understanding of crustal rheology, triggering phenomena and seismic hazard.Here, we revisit two recent earthquakes in the Zagros mountains (Iran) which exhibited unusual an...

We have examined the faulting in the 2012 August 11 Mw 6.4 and 6.3 Ahar (NW Iran) earthquakes using a combination of field mapping, remote-sensing observations of tectonic geomorphology, the cross-correlation of optical satellite images and the inversion of seismic waveforms. The first event was close to pure strike-slip, and the second was an obli...

The Tibetan Plateau is the largest orogenic system on Earth, and has been influential in our understanding of how the continental lithosphere deforms. Beneath the plateau are some of the deepest (∼100km) earthquakes observed within the continental lithosphere, which have been pivotal in ongoing debates about the rheology and behaviour of the contin...

We describe the geomorphology of a large (~10000 km2) internally draining region within the Zagros fold-and-thrust belt of Fars province, Iran. A series of wind gaps through fold crests and a continuous line of low-slope pixels in digital elevation models indicate the presence of an older, and now abandoned, through-going river system. We suggest,...

The potential for earthquakes along the plate boundaries has been mapped with reasonable success. Our attention should now focus on the threat posed by unanticipated quakes located in the continental interiors.

The 856 A.D. Qumis earthquake (M7.9) is the most destructive earthquake to have occurred in Iran, killing more than 200,000 people and destroying the cities of Damghan and the old Parthian capital of Shahr-i Qumis (Hecatompylos). This study combines evidence of historical seismicity with observations of the geomorphology and paleoseismology to prov...

The rheology of the lithosphere controls the transmission of stress within plates and the deformation that occurs at their boundaries. In oceanic regions determination of earthquake depths and of the elastic thickness show that the upper part of the lithosphere, where the temperature is less than 600oC, behaves as a brittle solid. At higher tempera...

The Zagros mountains of Iran are one of the most seismically active fold-and-thrust belts in the world, with frequent reverse faulting earthquakes of Mw 5 - 6 and rare larger events of up to Mw ~6.7. Earthquakes in the Zagros rarely rupture the surface, and there is a long-standing debate over whether faulting is restricted to the basement or also...

Regional shortening is accommodated across NE Iran in response to the collision of Arabia with Eurasia. We examine how N–S shortening is achieved on major thrust systems bounding the eastern branch of the Alborz (east of 57°E), Sabzevar and Kuh-e-Sorkh mountain ranges, which lie south of the Kopeh Dagh mountains in NE Iran. Although these ranges ha...

In our paper (Hollingsworth et al., 2008), we present a model of how the distribution of active faults in northeast Iran might accommodate both the northward motion of Central Iran and the westward motion of the South Caspian region, relative to Eurasia. We suggest the westward expulsion of the South Caspian region is accommodated by slip on the ri...

The active tectonics of Albania and surrounding regions, on the eastern margin of the Adriatic Sea, is characterized by subparallel thrust and normal faulting which, we suggest, is likely to be related to gravitational potential energy contrasts between the low-lying Adriatic Sea and the elevated mountainous areas inland. We calculate the magnitude...

This paper is concerned with the implications of earthquake depth distributions in the Himalayan–Tibetan collision zone for the general understanding of lithosphere rheology. In particular, recent studies have argued that microearthquakes in the uppermost mantle beneath Nepal and some earthquakes at 80–90 km depth, close to the Moho in SE and NW Ti...

The terrible disaster of the May 2008 Sichuan earthquake, which killed 70 000 people, is an example of a catastrophe that is likely to become more common in the future, particularly in Asia. Much of the population of Asia is now concentrated in poorly constructed cities that have grown very rapidly in places whose locations are closely related to t...

A central question in structural geology is whether, and by what mechanism, active faults (and the folds often associated with them) grow in length as they accumulate displacement. An obstacle in our understanding of these processes is the lack of examples in which the lateral growth of active structures can be demonstrated definitively, as geomorp...

Over the last 10 years a series of developments have led to a new understanding of what controls the variations in lithosphere strength, structure and evolution that produce dramatic contrasts between the geological histories of oceans, ancient shields and young orogenic belts. Those developments involve a wide range of observations from a great di...

The 2005 November 27 Qeshm Island earthquake (Mw 6.0) provides an excellent opportunity to study coseismic deformation in the Zagros Simply Folded Belt with Synthetic Aperture Radar interferometry (InSAR). Typical of reverse faulting in the Zagros, slip in the Qeshm Island earthquake did not rupture the surface. However, ascending and descending tr...

Taiwan is a region of rapid active tectonics, yet the study of the tectonic processes that shape the interior of the island is difficult due to the high rates of erosion and dense vegetation. We use digital topography to look for indications of active deformation preserved in the local geomorphology. In particular, anomalies in the regional pattern...

The south Caspian Basin is a relatively aseismic block within the Alpine-Himalayan Belt, but is surrounded by zones of high seismicity. We used the focal mechanisms of 16 earthquakes whose source parameters we determined from inversion of body waves and the mechanisms of 15 other earthquakes to determine the style of faulting in the seismic belts s...

In this paper we attempt to apply techniques that have recently been developed to describe distributed deformation on the continents to distributed deformation in subducting lithosphere slabs. We chose a part of the Tonga slab for this study because it has a simple, approximately planar, shape and high seismicity. We then used the spatial distribut...

We investigate a particular potential cause of deformation within the subducting Tonga slab: that associated with material that moves over a template while remaining in contact with it. In such a situation both the location and the style of deformation within the material depend, in a predictable way, on the shape of the template, and in particular...

Teleseismic waveforms, local ground acceleration, elevation changes, surface faulting and aftershocks are used to investigate the three-dimensional geometry of fault movement in the destructive earthquake (Ms= 6.9) of 1980 November 23 in Campania–Basilicata (southern Italy).Twelve kilometres of surface faulting has been identified following this ea...

The Kazerun Line is a transverse valley of about 200 km long that obliquely crosses the regular anticlines of the Zagros fold belt in SW Iran. At its northern end it is a clear fault which can be mapped on the surface. Anticline axes die out or bend towards this valley but do not cross it. Six moderate-sized earthquakes that occurred close the the...

The Bojnurd region of NE Iran experienced a Mw 6.4 earthquake on February 4, 1997. By combining results from teleseismic body-waveform analysis, field observations of structural damage, coseismic deformation, geomorphology, and analysis of the resulting strong ground-motions, we build a coherent picture of the faulting associated with this earthqua...

This paper examines how active faulting in the Turkey-Iran-Caucasus region accommodates the Arabia-Eurasia collision and the velocity field observed by GPS. The overall shortening across the zone is, in general, spatially separated (“partitioned”) into right-lateral strike slip in the Turkish-Iranian Plateau and thrusting in the Greater Caucasus. A...

This paper combines observations of seismicity, gravity, topography and thermal and velocity structures to investigate the rheological properties of the lithosphere in the Lake Baikal region. We examine the seismogenic thickness (Ts) using 25 earthquakes of Mw 5.1–7.1, whose full source parameters have been determined by inversion of teleseismic wa...

The 1994 Mw 6.0 and 2004 Mw 6.5 Al Hoceima earthquakes are the largest to have occurred in Morocco for 100 yr, and give valuable insight into the poorly understood tectonics of the area. Bodywave modelling indicates the earthquakes occurred on near-vertical, strike-slip faults with the nodal planes oriented NW–SE and NE–SW. Distinguishing between t...

The Kopeh Dagh is a linear mountain range separating the shortening in Iran from the stable, flat Turkmenistan platform. In its central part is an array of active right-lateral strike-slip faults that obliquely cut the range and produce offsets of several kilometres in the geomorphology and geological structure. They are responsible for major destr...

SUMMARY The catastrophic 2003 Mw 6.6 Bam earthquake in southern Iran attracted much attention, and has been studied with an abundance of observations from synthetic aperture radar, teleseismic seismology, aftershock studies, strong ground motion, geomorphology, remote sensing and surface field work. Many reports have focused on the details of one o...

The great earthquake belt which stretches from the Mediterranean through the Middle East into Central Asia results from the ongoing collision between the Eurasian plate and the African, Arabian and Indian plates to the south. Through much of this belt, the topography is created and controlled by fault movement in earthquakes. Many habitations are l...

Measurements of Be concentrations in quartz‐rich boulders exposed by the uplift of anticlinal ranges in Central Otago, New Zealand, are used to investigate the fault propagation styles and rates for the underlying blind reverse faults. Be ages along Little Rough Ridge reveal the propagation rate for this fault to be between zero (i.e., not propagat...

The westward motion of Turkey relative to Eurasia between the North and East Anatolian faults has been cited as one of the best examples of lateral transport of continental crust from a collision zone, in this case the Arabia-Eurasia collision. This process is variously called "escape" or "extrusion" tectonics. Range-parallel strike-slip faults wit...

In this paper, we use observations of earthquake source parameters and gravity to investigate the mechanical properties and the active faulting of the lithosphere in Mongolia. Well-determined earthquake centroid depths, including 10 from inversions of P and SH waveforms that are presented here for the first time, show that the seismogenic thickness...

Recent studies of the focal depths of earthquakes in old continental lithosphere have shown that they are almost entirely confined to the crust. Except where recent subduction of oceanic lithosphere is likely to have occurred, no earthquakes with a magnitude of > 5.5 have yet been located beneath the Moho. In contrast, in oceanic lithosphere earthq...

Be-10 concentrations measured in silica-cemented Tertiary sandstones in Central Otago have yielded minimum exposure ages of up to 1400 ka, some of the oldest ever recorded outside the dry valleys of Antarctica and some arid deserts. The silica-cemented sandstones outcrop as boulders in a region where their exposure is caused by the growth of anticl...

The Mw 6.4 Changureh (Avaj) earthquake occurred on 2002 June 22, in Qazvin province, northwest Iran. We use observations from seismology, field investigation and analysis of satellite imagery and digital topography to suggest that slip on a previously unrecognized thrust fault (herein named the Abdarreh fault) was responsible for the earthquake. In...

1] Right-lateral shear between central Iran and Afghanistan is accommodated on N–S right-lateral strike-slip faults surrounding the aseismic Dasht-e-Lut. North of $34°N, the right-lateral shear is accommodated on left-lateral faults that rotate clockwise about vertical axes. Little is known of the late Tertiary and younger offsets and slip rates on...

We examine the source mechanisms and depths of the largest earthquake that has occurred in the vicinity of Cyprus in the last 50 years, the 1996 October 9 earthquake (Mw= 6.8) and its principal aftershock on October 10 (Mw= 5.8). Being the first large event in the area for which seismic data from the global digital network are available, it provide...

The Arabia-Eurasia collision deforms an area of ∼3,000,000 km2 of continental crust, making it one of the largest regions of convergent deformation on Earth. There are now estimates for the active slip rates, total convergence and timing of collision-related deformation of regions from western Turkey to eastern Iran. This paper shows that extrapola...

The Dasht-e-Bayaz left-lateral strike-slip fault system in NE Iran ruptured over a length of ca 120 km during two earthquakes in 1968 and 1979. We constrain source parameters of the 1968 August 31 (Dasht-e-Bayaz) and 1979 November 27 (Khuli-Buniabad) earthquakes by analysing long-period body wave seismograms. Both earthquakes involved complex ruptu...

The Zagros mountains of SW Iran are one of the most seismically active intra-continental fold-and-thrust belts on Earth, and an important element in the active tectonics of the Middle East. Surface faulting associated with earthquakes is extremely rare, and so most information about the active faulting comes from earthquakes. We use long-period tel...

Previously unrecognised thrust faults in eastern Iran were responsible for a destructive earthquake at Tabas (1978, September 16), which produced over 80 km of distributed and discontinuous surface ruptures above a series of low anticlinal hills to the west of a major range-front. Analysis of long-period body-wave seismograms shows a simple rupture...

1] Earthquake focal depth distributions and effective elastic thickness variations on the continents suggest that in old cold regions such as shields, the lower continental crust can be stronger than the upper mantle, and imply that the upper mantle can flow even when the lower crust does not. However, in other place substantial flow in the lower c...

We use drainage reconstructions to estimate long-term offsets on the Gowk fault, an oblique right-lateral strike-slip fault in eastern Iran, on which there have been a number of recent large earthquakes. A 3 km horizontal offset is inferred from well-preserved geomorphology. We further identify a total cumulative offset of ∼12 km, which produces a...

We use drainage patterns, geological markers and geomorphological features to determine a right-lateral offset of ∼50 km, and possibly as much as ∼70 km, on the Main Recent Fault in NW Iran. This fault trends NW–SE and forms the NE border of the Zagros mountains. It accommodates the strike-slip component of the N–S convergence between Arabia and Eu...

Evidence from geomorphology, the distribution of large earthquakes, and geodetic measurements suggests that the active faulting in mainland Greece and the north Aegean Sea is concentrated into a small number of discrete, linear zones that bound relatively rigid blocks. On land, the zones are most clearly identified where the faulting is associated...

We use in situ cosmogenic 10Be measurements in quartzites to examine the growth and propagation rates of a Late Quaternary anticline forming above a blind reverse fault in Central Otago, New Zealand. We obtain average uplift and propagation rates of 0.10–0.15 mm yr−1 and 1.0–2.0 mm yr−1 respectively over the last 450 000 yr, though it is probable t...

We use observations of surface faulting, well-constrained earthquake focal mechanisms and centroid depths, and velocity structure determined by surface wave propagation and teleseismic receiver functions to investigate the present-day deformation and kinematics in and around the South Caspian Basin. The lack of earthquakes within the basin itself i...

Most of our knowledge about the deformation of the continents comes from observations made at the surface or within the seismogenic layer where faulting occurs in earthquakes. Yet the bulk of the lithosphere thickness deforms by creep, which probably becomes more distributed with depth. The extent to which motions at the surface are controlled by t...

We examine five areas of mainland Greece where active extension occurs on sub-parallel systems of normal faults, and where geomorphological and stratigraphic evidence indicates that the faulting has migrated basinwards into the original hanging walls, in several cases within the late Quaternary. By comparing fault slip rates estimated from geomorph...

We present a method to estimate self-consistent, continuous velocity field models given geologic or seismic strain rate and space-based geodetic observations. In a least-squares inversion, geologic or seismic strain rates are matched with continuous functions, subject to the constraint that GPS or VLBI observations are also matched by the model vel...

The Gurvan Bogd mountains of the Gobi–Altay, Mongolia contain a system of strike-slip faults with a reverse component, part of which moved in a large earthquake (Mw∼8.0) in 1957. Adjacent and sub-parallel to the main ranges are numerous thrust-related folds, thrust faults, and elongated low ridges (`forebergs'), all of which result from the shorten...

Patterns of activity on large faults in regions of distributed continental deformation can change quite rapidly (in less than 1 Ma). Such changes include faults becoming permanently or temporarily inactive, spatial migration of activity between different faults or faults sets within a deforming region, and faults apparently going through episodes o...

Deformation at the ends of large intracontential strike-slip faults that do not simply link other major structures often involves rotations about a vertical axis. We use earthquake slip vectors, surface rupture in earthquakes, and geomorphology to examine the ends of three major strike-slip faults in Mongolia. In these places a simple pattern is se...

Some parts of the east African rift system have deeper earthquakes (30-40 km), a larger effective elastic thickness (~35km), and wider half grabens (~50km) than are typical in other regions of continental extension. One such region is the southern part of the western branch of the east African rift in Malaw^i. In this region we describe a normal fa...

Central Otago in New Zealand is an area of active continental shortening in which a peneplain surface cut into schist has been deformed by folds, which are developed above buried reverse faults. We use the drainage patterns in this region to demonstrate various processes in fold (and fault) growth and interaction that would be difficult to identify...

Continental convergence between Arabia and Eurasia is taken up by distributed deformation in Iran. At wavelengths large compared with the thickness of the lithosphere this deformation is best described by a continuous velocity field. The only quantitative source of information on the spatial distribution of strain rates within Iran is the record of...

In this study we compare the strain rates obtained from earthquake moment tensors in the time interval 1911-92 in Greece with measured velocities of Satellite Laser Ranging (SLR) stations relative to Eurasia. We find that the SLR measurements do not require strain different in orientation from that seen in the earthquakes, but simply more of it. Th...

The 1968 Inangahua, New Zealand, earthquake occurred in the West Coast Basin and Range Province, northwest of the main plate boundary zone in northern South Island. At MS 7.4, it is not the largest known earthquake in the province, but it has been the subject of thorough seismological, geological, and geodetic documentation. Re interpretation of pa...

b The plate motion model NUVEL-1 predicts oblique convergence between the Pacific and Australian plates in the South Island of New Zealand. We used P and SH body waveform analysis to constrain the focal mechanisms of the 15 largest earthquakes (Ms > 5.8) that have occurred in this region since 1964, in order to see how the plate motion is accommoda...

Since 1964 there have been six earthquakes of Mw>=5.5 in east Africa whose centroid depths have been demonstrated to be in the range of 25-40 km. These depths are significantly greater than the 5- to 15-km range typical of most other regions of continental extension. The March 10, 1989 earthquake (Mw6.1) in Malawi is the first such deep event to ha...

A continuous horizontal velocity field describing the overall deformation of the lithosphere was obtained from the spatial distribution of seismic moment tensors of earthquakes in the Aegean Sea region over the time interval 1909-1983, using the method described by Holt et al. (1991). The velocity field obtained shows a motion of the southern part...

An optical laboratory matrix–vector processor is used to solve parabolic differential equations (the transient diffusion equation with two space variables and time) by an explicit algorithm. This includes optical matrix–vector nonbase-2 encoded laboratory data, the combination of nonbase-2 and frequency-multiplexed data on such processors, a high-a...

Optical laboratory system data for a linear quadratic regulator problem solution on an optical matrix-vector linear algebra processor are advanced. The accuracy of the closed loop poles of the system are used as the performance parameter. The optical laboratory system's performance in the solution of the associated nonlinear matrix equation was fou...

A space integrating optical linear algebra processor is described and laboratory performance of the system in the solution of nonlinear matrix equations for optimal control are presented. A new matrix partitioning method is described and the accuracy of the analog implementation of this processor is emphasized. This same architecture is capable of...

A new optical linear algebra processor architecture is described. Space and frequency-multiplexing are used to accommodate bipolar and complex-valued data. A fabricated laboratory version of this processor is described, the electronic support system used is discussed, and initial test data obtained on it are presented.

A Space Integrating (SI) Optical Linear Algebra Processor (OLAP) employing space and frequency-multiplexing, new partitioning and data flow, and achieving high accuracy performance with a non base-2 number system is described. Laboratory data on the performance of this system and the solution of parabolic Partial Differential Equations (PDEs) is pr...

A Space Integrating (SI) Optical Linear Algebra Processor (OLAP) is described and laboratory results on its performance in several practical engineering problems are presented. The applications include its use in the solution of a nonlinear matrix equation for optimal control and a parabolic Partial Differential Equation (PDE), the transient diffus...

Reference is made to a study by Casasent et al. (1983), which gave a description of a frequency-multiplexed acoustooptic processor and showed how it was capable of performing all the individual operations required in Kalman filtering. The data flow and organization of all required operations however, were not detailed in that study. Consideration i...

In this paper, we consider the use of residue arithmetic to increase the accuracy and reduce the dynamic range requirements of optical matrix–vector processors. We show that matrix–vector operations and iterative algorithms can be performed totally in residue notation. We suggest an architecture using a frequency-multiplexed optical systolic array...

Optical matrix processors using acoustooptic transducers are described with emphasis on new systolic array architectures using frequency multiplexing in addition to space and time multiplexing. A Kalman filtering application is considered as our case study from which the operations required on such a system can be defined. This also serves as a new...