Geology

Estimation of elastic anisotropy, which is usually caused by rock fabrics and mineral orientation, has an important role in exploration seismology and better understanding of crustal seismic reflections. If not properly taken care of during processing steps, it may lead to wrong interpretation or distorted seismic image. In this thesis, a state-of-the-art under the development Laser Doppler Interferometer (LDI) device is used to measure phase velocities on the surface of rock samples from a major deformation zone (Österbybruk Deformation Zone) in the Bergslagen region of eastern Sweden. Then, a general inversion code is deployed to invert measured phase velocities to obtain full elastic stiffness tensors of two samples from the major deformation zone in the study area. At the end, results are used to correct for the anisotropy effects using three dimensionless Tsvankin's parameters and a non-hyperbolic moveout equation. The resulting stacked section shows partial reflection improvement of the deformation zone compared with the isotropic processing section. This suggests that rock anisotropy may also contribute to the generation of reflections from the deformation zones in the study area but requires further investigations. I I would like to express my deepest appreciation to all those who provided me the possibility to complete this thesis. A special gratitude I give to my supervisor, Dr. Alireza Malehmir, whose contribution in productive suggestions and encouragement, helped me to complete this thesis. Special thanks go to my dearest friends, Taher Mazloumian, Ershad Gholamrezaie, Hanieh Shahrokhi, Amir Abdi, Omid Ahmadi, Ashkan Dorostkar and Magnus Andersson who helped me with their useful comments and suggestions about my thesis. I have to appreciate the guidance given by other professors and supervisors especially in my project presentation that has improved my presentation skills thanks to their comments and advices. Furthermore, I would also like to thank: • Dr. Robert W. Vestrum for letting me run his codes and use his helpful advices. • Geological Survey of Sweden for financially supporting the Dannemora data acquisition and collecting rock samples. • Dr. Maxim Lebedev for his corporation during laboratory measurements. • GLOBE Claritas T M under license from the Institute of Geological and Nuclear Sciences Limited, Lower Hutt, New Zealand was used to process the seismic data. • This master thesis has been done in collaboration with Curtin University in Perth.

Background and Objective: Cleanroom is a tightly enclosed environment where airborne particles are under control and is a necessary environment in pharmaceutical industries to produce quality products. Hence, we sought to assess and simulate particle dispersion and track particles in a cleanroom by computational fluid dynamics (CFD) method in a pharmaceutical industry. Materials and Methods: This experimental study was conducted in 2015 in a pharmaceutical industry. We evaluated particle concentration and number in the cleanroom according to ISO 14644 -3 standard. In addition, air flow pattern and particle dispersion in the cleanroom with cleanliness class of C was simulated based on CFD. The results showed that the path of particle movement and distribution and dispersion of particles in the cleanroom are completely dependent on flow shape and the pattern of air flow in the cleanroom. Furthermore, the simulation results showed that wall return had efficiency of higher than 70% for particle sizes of 0.5 and 5 microns. Equipment and tools existing in the cleanroom affect the air flow pattern, and in turn, particle removal efficiency. Moreover, particle dispersion simulation in the cleanroom illustrated that air flow pattern exerts the highest impact on particle removal in cleanrooms.

As one of the major Phanerozoic orogenic belts on Earth, the Palaeo-Tethyan orogenic system along the southern Eurasian margin is characterized by multiple magmatic, sedimentary, metamorphic and mineralization events, recording the oceanic basin closure and terrane accretion during the convergence of Cimmerian microplates. A systematic study of these petrological and metallogenic records is beneficial to understand the assembling processes of the Cimmerian terranes, and thus helps to reconstruct the pre-Cenozoic evolution history of the Tethyan orogenic system. Although important advances have been made over the last decades, many parts of this orogenic system are poorly studied, and some key scientific problems need to be further studied by multidisciplinary integrated approaches. Therefore, we launched a Research Topic in Frontiers in Earth Science to discuss 1) Tethyan tectonic evolution and dynamic processes; 2) sediment provenance and paleogeographic reconstructions within the Tethyan realm; 3) geodynamic similarities and differences in other tectonic realms. This Research Topic collects 10 papers from different disciplines, which helps to understand the tectonic evolution and geodynamic processes in the Tethyan realm. Among them, three articles focus on sedimentary provenance, sedimentary structure and tectonic implications. For example, Han et al. studied the provenance of the Lower Triassic Qingtianbao Formation in the southwestern margin of the South China Craton. Their results suggest that the Palaeo-Tethyan Ocean may undergo unidirectional subduction westward beneath the Indochina Block during the Late Permian-Early Triassic, providing an important constraint to the subduction polarity of the Eastern Tethyan ocean. Lv et al. studied the sandstone petrography and detrital U-Pb age of the Lower Jurassic Baitianba Formation from the Sichuan Basin, which helps to understand the pre-collisional tectonic evolution of the basin-mountain system at the margin of the

Observation of electromagnetic earthquake precursors has been studied in Extremely Low Frequency (ELF) band of 10-300Hz at about forty locations in Japan for these twenty years. Although the ELF band has a small perturbation owing to solar-terrestrial and lightning noises, salient tectonic electromagnetic radiation was clearly extracted through ultra-long period wavelet analysis.

1. Department of Earth Sciences, Graduate School of Science, Chiba University, 2. Graduate School of Science and Engineering, Chiba University, 3. Southern University of Science and Technology, China, 4. Hokkaido University, 5. Kyoto University, 6. Nagoya Institute of Technology, 7. Aichi Prefectural University, 8. Aichi University, 9. Chubu University, 10. Nihon University, 11. Osaka University, 12. Tokyo Gakugei University, 13. The University of Electro-Communications, 14. National Central University, Taiwan, 15. Chapman University, US, 16. University of Basilicagta, Italy

The huge earthquake of M9.0 hit the East North Japan off the Pacific Ocean on March 11, 2011. We have obtained the ELF band (223/233Hz) electromagnetic radiation data of the quakes for ten years. The radiation consists of the sferics reflected from the lower ionosphere of 45-60km height with modulation by the quake's induced electric field. In this paper, analytical methods for detecting earthquake precursors are discussed.

Electromagnetic wave precursor at ELF band of 223Hz on the occasion of the M5.8 East Yamanashi-prefecture earthquake in the central Japan is discussed. It was monitored at five locations ranging from 50km to lOOOkm. These multi-location data supplied us a new method to analyze and to clear up precursor through a time and spatial correlation and normalization technique by making use of the received tropical thunder noise as a reference for all spots. The precursor• is consisted of two factors of the locally radiated signal at the preparing area and the modification of radiation characteristic by ionosphere. And the big disturbances are discriminated as solar flare and lightning noises by time shifting as the movements of earth and lightning cloud. Further, we propose a radiation model of precursor based upon the dipole source equivalently transferred on, the earth surface regardless of source origin which is inside the deep crust or near the earth surface. On the strength of the model, we can estimate precursor level, detectability and a preferable arrangement of sensor to monitor a disastrous M6-class inland earthquake.

Com o objetivo de identificar o tipo de herança, o número de genes e os parâmetros genéticos e fenotípicos da resistência do acesso PI 595201 a um isolado de PRSV-W da região Norte do Brasil foi conduzido um experimento na área experimental do Departamento de Produção Vegetal da Universidade Federal do Tocantins, em condições de casa de vegetação. A partir do cruzamento entre a cultivar suscetível Crimson Sweet (P1) e o acesso resistente PI 595201 (P2) foi obtida a geração F1 e as gerações segregantes, cujas plantas foram inoculadas e avaliadas quanto à resistência com base nos sintomas nas folhas. Foram avaliadas 48, 48, 80, 200, 100 e 100 plantas das gerações P1, P2, F1, F2, RC11 e RC12, respectivamente, em delineamento inteiramente casualizado com quatro repetições. A partir da análise de componentes de médias no controle da resistência determinaram-se dois genes, predominando os efeitos gênicos aditivos, seguido de efeitos de dominância incompleta no sentido de aumentar a resist...

The study was carried to determine the mineralogy of soils of different geomorphic units for providing the more detailed information needed to improve agricultural production in north-eastern part of Haryana. The soils of the study area were slightly acidic to strongly alkaline in reaction (6-9.4). The cation exchange capacity and electrical conductivity varied from 3.10-26.80 cmol (+) kg-1 and 0.16-1.20 dSm-1, respectively. In general, the soils were siliceous in nature with SiO2 ranging from 68.60 to 87.90 percent. The soil samples from surface and subsurface diagnostic horizons were studied through X-ray diffraction. In fine sand, quartz was the dominant mineral followed by feldspars, muscovite, hornblende, tourmaline, zircon, biotite, iron ores and sphene. In silt fraction, quartz was the dominant mineral followed by mica, feldspars, chlorite, kaolinite, interstratified and traces of smectite and vermiculite. Semi-quantitative estimation of clay fraction indicated that illite wa...

Dual WAZ and tilted orthorhombic anisotropy model building and imaging has approved to provide a more geologic conforming high resolution velocity models, give a better illumination and flatten the common imaging gathers for all azimuths, and improve the CIG flatness and enhance seismic continuity. In this paper we will present wide azimuthal orthorhombic anisotropy model building workflow and multiazimuth modelling for orthogonal WAZ, compare the TORT initial and final models in depth sections and slices, and show some examples of final TORT seismic imaging and CIG comparison to demonstrate the orthorhombic anisotropy modelling improves the CIG flatness across the different azimuths.

Several wide-azimuth (WAZ) surveys in the Gulf of Mexico have been acquired to resolve the structure in a complex subsalt region. Long-offset wide-azimuth data can be very beneficial over conventional wide-azimuth acquisition in terms of imaging deeper targets and steeply dipping complex overhangs. Whenever seismic waves encounter layered media, the velocity they experience parallel to the layering is often greater than the velocity perpendicular to the layering. A transversely isotropic (TI) job flow results in improved imaging for these geological regimes. When sediment layering demonstrates considerable dip, tilted-transverse isotropy (TTI) can improve the imaging over verticaltransverse isotropy (VTI), which best describes purely horizontal layers. In the presence of fractures within thin layered media, it has been observed on multiazimuth data that VTI and TTI approaches are not sufficient in resolving conflicting azimuthally varying residual moveout (RMO) on the common-image gathers (CIG's). However, extending the velocity model from TTI to orthorhombic anisotropy can resolve the discrepancy in the moveout observed for a CIG across different azimuths. In this paper we will present a case study demonstrating a method of improving subsalt imaging using image-guided tilted orthorhombic (IG-TORT) tomography and imaging on newly-acquired long-offset wide-azimuth Declaration data. In addition, the data is combined with the existing Justice WAZ data in the Gulf of Mexico.

In depth migration for marine seismic data, the water-layer related multiples will cause severe artifacts in migration images, sometimes misguiding interpretation. For a deepwater case, we always use surface related multiple elimination (SRME) to suppress the multiples. In recent years, the shallow water multiple elimination (SWME) method is also developed for tackling multiples where the water bottom is relatively shallow (<100m). Furthermore, poststack wave-equation based multiple prediction and subtraction methodology can be utilized to remove residual multiples. In this study, we applied SWME on the original shot gathers followed by the depth migration, using the demultipled data for input. After stacking, we also applied the wave-equation based poststack multiple prediction and subtraction on the stacked image. Comparing the results before and after multiple removals, we can see dramatic improvement in the subsalt area.

The ultimate goal for seismic depth imaging is to find new hydrocarbon prospects or improve existing ones. High quality seismic data and an accurate velocity model are the main drivers for good imaging. Prospects may be identified on seismic data in areas which can range from high to low signal. Roughly speaking, prospects generated for shallow targets will be on good signal data and prospects for deeper targets will be in low signal areas, with the signal strength somewhere in between for the midrange depths. Different imaging approaches, including migration algorithms and velocity model building techniques, are needed for the different situations of varying geology and signal-to-noise ratios. In areas of high signal, tomography is useful for refining the velocities for three-way (e.g. fault traps) or four-way depth closures. Where signal-to-noise is lower, more modern tools will be required. Areas of medium signal might include salt overhangs and fold-and-thrust belts, where we might want to define closure under a high angle thrust fault. These areas could benefit from Reverse Time Migration (RTM) based Delayed Imaging Time (DIT) scans. For deeper targets where the signal is often low, efficient RTM layer stripping can be very effective for improving the imaging of plays below salt or beneath a detachment or unconformity. We are presenting a case study showing improvement in the overall imaging in terms of fault closure, subsalt sediments truncating against the salt flanks, and better focusing around the salt overhang in an area of the Gulf of Mexico (GOM). This paper will demonstrate the benefit of tomography for sediment velocity model building and updating for depth imaging, along with the improvements gained by using RTM based DIT scans and layer stripping RTM.

L’articolo presenta i principali risultati di esperimenti eseguiti su nodi trave-pilastro innovativi realizzati con struttura composta acciaio e calcestruzzo. Trattasi di cinque prove in cui altrettanti nodi a due vie in scala reale sono sottoposti a spostamenti pseudo-statici di tipo ciclico tali da indurre una condizione di sollecitazione di tipo sismico. Quattro nodi hanno le travi di tipologia mista acciaio e calcestruzzo ed un nodo e interamente in calcestruzzo armato normale per stabilire utili confronti. Per quanto riguarda i primi quattro, due nodi hanno i pilastri in c.a., un nodo e realizzato con pilastro con camicia di acciaio di sezione quadrata ed infine un nodo ha anche i pilastri in struttura reticolare mista. I risultati ottenuti sono analizzati criticamente e confrontati tra loro per poter trarre utili conclusioni sulla duttilita e sulla resistenza dei nodi innovativi nei confronti delle sollecitazioni di natura sismica.

Long term Atlantic tropical storm activity is described by the time series of the yearly Accumulated Cyclone Energy (ACE) Index for the time interval 1851-2007. ACE is a measure of total wind energy for North Atlantic basin and land falling tropical cyclone activity. Since the ACE index reflects a combination of storm intensity and duration it is a better measure of overall activity and likely damage than the number of either basin or land falling tropical storms or hurricanes. The yearly ACE time series is non-stationary, and one step toward detecting possible long-term quasi-periods is to detrend the original data. In this paper, we use a procedure for data transformation by which ACE index is fitted in least square sense with polynomials of increasing order, followed by detrend. It is shown that, with some approximation, the obtained time series is cyclostationary, and a multi-decadal oscillation is detectable, as indicated by the power spectrum analysis.

In a first approximation, the Earth's interior has an isotropic structure with a spherical symmetry. Over the last decades the geophysical observations have revealed, at different spatial scales, the existence of several perturbations from this basic structure. In this paper we discuss the hemispheric perturbations induced to this basic structure if the inner core is displaced from the center of mass of the Earth. Using numerical simulations of the observed hemispheric asymmetry of the seismic waves traveling through the upper inner core, with faster arrival times and higher attenuation in the Eastern Hemisphere, we estimate that the present position of the inner core is shifted by tens of kilometers from the Earth's center eastward in the equatorial plane. If the only forces acting on the inner core were the gravitational forces, then its equilibrium position would be at the Earth's center and the estimated displacement would not be possible. We conjecture that, due to interactions with the flow and the magnetic field inside the outer core, the inner core is in a permanent chaotic motion. To support this hypothesis we analyze more than ten different geophysical phenomena consistent with an inner core motion dominated by time scales from hundreds to thousands of years.

Longitudinal dispersion coefficients in given realizations of the transport computed by two currently used approximations of the first-order in velocity variance are compared with accurate global random walk simulations. The comparisons are performed for the same ensemble of realizations of the Darcy velocity field, approximated by a quasi-periodic random field, for log-normal hydraulic conductivity with small variance and finite correlation lengths. The results show that, at finite times of about one dispersion time scale, the mean coefficient is underestimated by ≈ 20% and the fluctuations are overestimated by ≈ 80%. At larger times the errors decrease monotonously and the first-order approximations yield fairly good predictions for the mean and the fluctuations of the dispersion coefficient.

Deformation monitoring is a crucial matter to avoid catastrophic failure due to extraction of resources. Radar data, mainly synthetic apreture radar (SAR) data and their diverse techniques are suitable for deformation monitoring. This paper provides a review of SAR data and their techniques for deformation monitoring. It also provides a brief description of Image acquisition, SAR geometry, SAR development, satellite specifications, and commercial software used for Interferometry and deformation monitoring. In the end, it is concluded that the existing SAR techniques are capable of accurate monitoring of land deformation. It is also concluded that persistant InSAR (PSInSAR) gives better results than differential InSAR (DInSAR).

The present study attempts to understand the seasonal and spatial variations in the physico-chemical (temperature, pH, salinity, dissolved oxygen, and nutrients) and productivity characteristics of the northern Arabian Sea off the Indian coast. Samples were collected from four different sites off the Veraval coast. The values of the physical and chemical variables were higher during the summer season, whereas nutrient concentrations were high during the winter season due to the maturity of intake nutrients during post-monsoon and winter convective mixing during the northeast monsoon. The dissolved oxygen (DO) concentration was strongly and positively correlated with the net primary productivity (NPP) and chlorophyll a (Chl-a) content to support productivity along the region. Dissimilarity in study variables was observed between the inshore and offshore locations. Principal component analysis revealed a strong relationship between nutrients and productivity variables (Chl-a and NPP). Nutrient levels were high at inshore sites, which can be attributed to the heavy nutrient load from land-based anthropogenic activities and impact due to natural processes like water mixing, sedimentation, and wave activities. Nutrients were strongly and positively correlated with the productivity variables, i.e., Chl-a and NPP. Chl-a positively correlated with NPP (r = 0.90), which indicates that it is a principle productivity pigment in the marine ecosystem.

Prominent geothermal systems of Africa are associated with the Great Rift Valley located in the eastern part of Africa. It intersects Djibouti, Eritrea, Ethiopia, Kenya, Tanzania Zambia, Malawi and northern Mozambique. There is a western segment that passes through Uganda, Rwanda and Burundi. All these countries have some geothermal potential. It is only in Kenya and Ethiopia that exploitation of geothermal energy for power generation has been attempted. The North African countries including Egypt, Tunisia, Algeria, Libya and Morocco have low temperature resources not associated with the African Rift system. These resources have been used primarily for agriculture and bathing. Tunisia is a leader for greenhouse heating and irrigation. Electricity generation from geothermal in Kenya started in 1981 with construction of Olkaria I station. The current output in Kenya is 130MW which is about 11% of the country’s effective capacity. There is a plan to increase the generation by an additi...

The strongest documented seismic disaster ever occurred in the Po Plain area (January 3, 1117, M = 6.5) involved significant damage over a large zone. The genetic mechanism of such an event, most probably caused by more than one earthquake, is still an object of debate. Above all, the sources so far proposed cannot account for significant features of the observed macroseismic field. In this work, we suggest that the damage in the Verona zone was caused by the activation of a fault in the Lessini tectonic district, while damage in the central Po Plain may be related to a thrust fault located beneath the Giudicarie belt. The effects felt in northern Tuscany might derive from the seismic activation of the presumed SW-ward buried prolongation of the Giudicarie fault. The presence of such transpressional lithospheric discontinuity in the Adriatic domain since the upper Miocene and its reactivation (Pliocene-Pleistocene) as a thrust zone is mainly suggested by an accurate analysis of the observed deformation pattern in the central Mediterranean region. The proposed Giudicarie source may also help to explain the damage observed in the central Po Plain on December 25, 1222, which is not compatible with the seismic sources so far proposed.

The seismic stratigraphy of the western McMurdo Sound region has been reevaluated in response to the apparent 8 m y . discrepancy in the age of seismic units traced between the CRP-1 drillhole located off Cape Roberts and the CIROS-1 drillhole, located 70 km further south. All the available seismic reflection in the region, including new single and multi-channel seismic data recorded in the region in 1996 by RIV N B PALMER, have been compiled and reanalysed to develop a consistent interpretation of the seismic units in the region, using the seismic stratigraphy of . The interpretation has been based on the original interpretation of seismic units in the data recorded by the RIV S. P. LEE (Cooper & Davey, 1987) and has been traced across the region to the CRP-1 drillsite. A crucial correlation at the CRP-1 site is for the boundary between the Units V3 and V4. This unconformity lies at depth east of the drillsite and the associated reflection event has been traced to the CRP-l site in two ways; one directly across the Roberts Ridge, where it has to be traced through the seafloor multiple, and the second through deep water north of Roberts Ridge. The two correlation pathways result in a discrepancy of about 100 m where the unconformity intersects CRP-l. If the correlation across Roberts Ridge is correct then the strata equivalent to 3 18 m in CIROS-1 will, at the CRP-1 site, be 21 thick and the V 3 N 4 boundary lies 163 mbsf. If the alternative is correct then the equivalent strata at the CRP-1 site will have also reduced in thickness, but only to about 120 m, and the V3N4 boundary lies around 250 mbsf.

A late Quaternary, current-lain sediment drift deposit over 30 m in thickness has been discovered on the continental shelf of East Antarctica in an 850 m deep glacial trough off George Vth Land. Radiocarbon dating indicates that a period of rapid deposition on the drift (averaging 290 cm/kyr) occurred in the mid-Holocene, between about 3000 and 5000 yr before present (yr bp). Slower deposition rates of around 10 cm/kyr, during the past 0±3000 yr and from 5000 to about 13000 yr bp, coincides with the deposition of bioturbated, ice-rafted debris (IRD) rich, sandy mud under an energetic bottom current regime. In contrast, the mid-Holocene (3000±5000 yr bp) sediments are ®ne-grained, laminated to cross-laminated with minimal IRD content, and are contemporaneous with a period of warmer marine conditions with less sea ice production. This pattern suggests that bottom currents were weaker than present day in the mid-Holocene, and that the rate of dense bottom water production was reduced at that time. This scenario is consistent with the hypothesis of non-steady state rates of Antarctic bottom water production through the Holocene as recently proposed by Broecker and his colleagues.

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We describe and present results from a finite-volume (FV) parallel computer code for forward modelling the Maxwell viscoelastic response of a 3-D, self-gravitating, elastically compressible Earth to an arbitrary surface load. We implement a conservative, control volume discretization of the governing equations using a tetrahedral grid in Cartesian geometry and a low-order, linear interpolation. The basic starting grid honours all major radial discontinuities in the Preliminary Reference Earth Model (PREM), and the models are permitted arbitrary spatial variations in viscosity and elastic parameters. These variations may be either continuous or discontinuous at a set of grid nodes forming a 3-D surface within the (regional or global) modelling domain. In the second part of the paper, we adopt the FV methodology and a spherically symmetric Earth model to generate a suite of predictions sampling a broad class of glacial isostatic adjustment (GIA) data types (3-D crustal motions, long-wavelength gravity anomalies). These calculations, based on either a simple disc load history or a global Late Pleistocene ice load reconstruction (ICE-3G), are benchmarked against predictions generated using the traditional normal-mode approach to GIA. The detailed comparison provides a guide for future analyses (e.g. what grid resolution is required to obtain a specific accuracy?) and it indicates that discrepancies in predictions of 3-D crustal velocities less than 0.1 mm yr -1 are generally obtainable for global grids with ∼3 × 10 6 nodes; however, grids of higher resolution are required to predict large-amplitude (>1 cm yr -1 ) radial velocities in zones of peak postglacial uplift (e.g. James bay) to the same level of absolute accuracy. We conclude the paper with a first application of the new formulation to a 3-D problem. Specifically, we consider the impact of mantle viscosity heterogeneity on predictions of present-day 3-D crustal motions in North America. In these tests, the lateral viscosity variation is constructed, with suitable scaling, from tomographic images of seismic S-wave heterogeneity, and it is characterized by approximately 2 orders of magnitude (peak-to-peak) lateral variations within the lower mantle and 1 order of magnitude variations in the bulk of the upper mantle (below the asthenosphere). We find that the introduction of 3-D viscosity structure has a profound impact on horizontal velocities; indeed, the magnitude of the perturbation (of order 1 mm yr -1 ) is as large as the prediction generated from the underlying (1-D) radial reference model and it far exceeds observational uncertainties currently being obtained from space-geodetic surveying. The relative impact of lateral viscosity variations on predicted radial motions is significantly smaller.

Predictions of present day secular variations in the Earth's long wavelength geopotential driven by glacial isostatic adjustment (GIA) have previously been analyzed to infer the radial profile of mantle viscosity and to constrain ongoing cryospheric mass balance. These predictions have been based on spherically symmetric Earth models. We explore the impact of lateral variations in mantle viscosity using a new finite-volume formulation for computing the response of 3-D Maxwell viscoelastic Earth models. The geometry of the viscosity field is constrained from seismic-to-mographic images of mantle structure, while the amplitude of the lateral viscosity variations is tuned by a free parameter in the modeling. We focus on the zonal J ˙S harmonics for degrees S = 2,. . .,8 and demonstrate that large-scale lateral viscosity variations of two to three orders of magnitude have a modest, 5-10%, impact on predictions of J ˙2. In contrast, predictions of higher degree harmonics show a much greater sensitivity to lateral variation in viscosity structure. We conclude that future analyses of secular trends (for degree S N 2) estimated from ongoing (GRACE, CHAMP) satellite missions must incorporate GIA predictions based on 3-D viscoelastic Earth models.

This research project explores the behaviour of laterally loaded piles in two different case studies with 3D FEM. A general understanding of the laterally loaded piles was reviewed with the insights of the behaviour of single pile or pile groups subjected to horizontal loading. This research project explores different method of analysis for laterally loaded piles and how 3D FEM could best be used as a reliable tool to predict the behaviour of the laterally loaded piles. The contribution to knowledge could be better understanding on the mechanism of laterally pile by using 3D FEM. A proper understanding of load transfer mechanism for pile is necessary for analysis and design. The natural of lateral loading can be divided into 'active' loading and 'passive loading' as suggested by Fleming . Reese & Van Impe [15] considered the active loading as 'timedependent or live loading' and passive loading as 'timeindependent or dead loading'. The active loading could be in the form of wind, wave, current, scour, ice, ship impact; and loads from other sources. Whereas, the passive loading, in the form of earth pressure, moving soil and thrusts from dead loading of structures is also noted. A study of several types of analysis method and the soil-structure interaction of laterally loaded pile would show the options and suitability for a practical method. Although many methods had been proposed by researchers to solve such problems, the reliability and uncertainties of such methods are open for discussion. Conventional analytical methods such as Broms' theory, Winkler approach, p-y method and Elasticity theory do require assumptions and empirical data to solve or provide some insights, which can be ambiguous in term of analysis. As such, the 3D FEM is a more reliable and easier tool to study behaviour of laterally loaded piles. The comparison of p-y method and finite element analyses was validated with a case study. The comparison of centrifuge model and finite element analyses was also validated with another case study. Literature review shows that many researchers [1, 4, 8, 9, 18] favour p-y method and they have proposed a lot of improvement or development to it. However, this method uses a p-y curve as an input to a finite difference program for solutions. In the past, the development of p-y curve is based on centrifuged or full-scale experimental data , and the formulation of p-y curve can be characterized under sand and clay. Recent papers from use finite element analysis to generate p-y curve for single pile and pile groups. Their process is rather tedious, but the advantage of p-y method can provide profile of deflection and bending moment of the laterally loaded pile as compared to other methods. But in other means, 3D FEM analysis can better provide better prediction with substantial number of parametric analyses.

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A new type of Lophosteus-finspine ist described. This fragment shows, that Lophosteus and Andreolepis may belong neither to the actinopterygians nor to the sarcopterygians. At present it is impossible to establish its relationships. K u r z f a s s u n g : Ein neuer Typ eines Lophosteus-Flossenstachels wird beschrieben. Dieser Rest zeigt, daf~ es sich bei Lophosteus und Andreolepis weder um Actinopterygier noch um Sarcopterygier handeln kann. Es ist beim derzeitigen Kenntnisstand jedoch noch nicht m6glich, die Beziehungen zu anderen niederen Vertebraten zu kl~iren. Im Jahre 1856 beschrieb PANDEI~ aus dem oberen Silur (Pridoli) des Ohesaare-Kliffs SW-Kiiste der Insel C)sel (= Saaremaa, Estland) Knochenbuchstfickchen von Fischen, die er teils dem Antiarch Pterichthys, teils einer von ihm hierfiir neu aufgestellen Gattung Lophosteus zuwies. Da damals noch nicht die Priiparation phosphatischer Fossilien in Kalken durch Essigs~iure bekannt war, stand ihm fiir seine Beschreibungen nur wenig Material zur Verfiigung. Auch der niichste Bearbeiter, ROHON (1893), konnte nur einige Knochenbruchstficke untersuchen. Immerhin war es RoHoN m6glich, von seinem Material Dfinnschliffe anzufertigen und die Histologie der Reste erstmals zu beschreiben. Aus den dabei gemachten Beobachtungen zog er folgende Schliisse: -alle Reste k6nnen unter dem Namen Lophosteus vereinigt werden; -die Reste geh6rten seiner Meinung nach nicht zu den Antiarchi, sondern zu den Holoptychida, das heitgt zu den Knochenfischen (Osteichthyes = Teleostomi). Der niichste Bearbeiter der Gattung Lophosteus war erst WALTER GROSS. Nachdem er 1968 fragliche Actinopterygierschuppen aus dem Obersilur von Gotland als Andreolepis hedei beschrieben hatte, konnte er 1969 und 1971 Schuppen, Zahnknochen, isolierte Einzelz~ihne und Bruchstiicke von Deckknochen mit Spuren des Sinnesliniensystems von Lophosteus superbus PANDER beschreiben. Ffir diese Untersuchungen stand Gl~oss eine sehr viel gr6t~ere Materialmenge (auch fiir eine grof~e Zahl von Diinnschliffen) als den beiden friiheren Bearbeitern zur Verffigung, da er Lophosteus-reiche Geschiebe in verdiinnter Essigs~iure aufl6ste. Die systematische Stellung konnte trotz der morphologischen Ahnlichkeit mit Actinopterygier-Schuppen nicht endgiiltig abgesichert werden. GRoss konnte * Anschrift des Autors: Dipl.-Geol. MARKUS OTTO,

We present a new 3-D seismic structural model of the eastern Indonesian region and its surroundings from full-waveform inversion (FWI) that exploits seismic data filtered at periods between 15 -150 s. SASSY21 -a recent 3-D FWI tomographic model of Southeast Asia -is used as a starting model, and our study region is characterized by particularly good data coverage, which facilitates a more refined image. We use the spectral-element solver Salvus to determine the full 3-D wavefield, accounting for the fluid ocean explicitly by solving a coupled system of acoustic and elastic wave equations. This is computationally more expensive but allows seismic waves within the water layer to be simulated, which becomes important for periods [?] 20 s. We investigate path-dependent effects of surface elevation (topography and bathymetry) and the fluid ocean on synthetic waveforms, and compare our final model to the tomographic result obtained with the frequently used ocean loading approximation. Furthermore, we highlight some of the key features of our final model -SASSIER22 -after 34 L-BFGS iterations, which reveals detailed anomalies down to the mantle transition zone, including a convergent double-subduction zone along the southern segment of the Philippine Trench, which was not evident in the starting model. A more detailed illumination of the slab beneath the North Sulawesi Trench reveals a pronounced positive wavespeed anomaly down to 200 km depth, consistent with the maximum depth of seismicity, and a more diffuse but aseismic positive wavespeed anomaly that continues to the 410 km discontinuity.

The region of Jakarta and its vicinity is one of the least understood geological domains in Java Island, Indonesia. Yet, the region is one of the few places which are often impacted by earthquakes from the Indo-Australian Plate subduction zone as well as on land active faults. In this study, a borehole seismic experiment was designed to unravel the seismic activity of the Baribis Fault, which continues and leads to Jakarta. This passive source experiment was composed of seven broadband instruments that extended across the Jakarta region and surrounding areas. The experiment recorded seismic data from the end of July 2019 to August 2020. We located 91 events of hypocenter location determination of the data recording; one event was located closely to the Baribis Fault line that continues to Jakarta and was felt in Bekasi (Southeast of Jakarta) at up to II-III on the Modified Mercalli Intensity (MMI) scale. The focal mechanism solution of this event shows an oblique thrust fault type. ...

High seismicity rates in and around West Java and Sumatra occur as a result of the Indo-Australian plate converging with and subducting beneath the Sunda plate. Large megathrust events associated with this process likely pose a major earthquake and tsunami hazard to the surrounding community, but further effort is required to help understand both the likelihood and frequency of such events. With this in mind, we exploit catalog seismic data sourced from the Agency for Meteorology, Climatology, and Geophysics (BMKG) of Indonesia and the International Seismological Centre (ISC) for the period April 2009 through to July 2020, in order to conduct earthquake hypocenter relocation using a teleseismic double-difference method. Our results reveal a large seismic gap to the south of West Java and southeast Sumatra, which is in agreement with a previous GPS study that finds the region to be a potential future source of megathrust earthquakes. To investigate this further, tsunami modeling was ...

Local seismic tomography is a well-known and commonly used method for obtaining detailed information about the internal structure of volcanoes. The eruption of Mt. Agung in 2017 was a vital opportunity scientifically because it is the first eruption that had sufficient seismic observation networks to carry out local seismic tomography at this volcano. In this study, we investigate the subsurface structure of Mt. Agung in Bali, which is one of the highest risk volcanoes in Indonesia. We conducted travel-time tomography using P- and S-wave arrival times of volcano-tectonic (VT) events to determine the three-dimensional (3D) Vp, Vs, and Vp/Vs ratio structure beneath Mt. Agung. We used 1,926 VT events, with corresponding 9482-P and 8683-S wave arrival times recorded by eight seismic stations over an observation time spanning from October 18 to December 31, 2017. We obtain the hypocenter solution for VT events using the maximum likelihood estimation algorithm and use an optimum 1D veloci...

We reveal the existence of a previously unknown fault that generated the Mw 7.3 Flores Sea earthquake, which occurred on 14 December 2021, approximately 100 km to the north of Flores Island, in one of the most complex tectonic settings in Indonesia. We use a double-difference method to relocate the hypocenters of the mainshock and aftershocks, determine focal mechanisms using waveform inversion, and then analyze stress changes to estimate the fault type and stress transfer. Our relocated hypocenters show that this earthquake sequence ruptured on at least three segments: the source mechanism of the mainshock exhibits dextral strike-slip motion (strike N72°W and dip 78° NE) on a west–east-trending fault that we call the Kalaotoa fault, whereas rupture of the other two segments located to the west and east of the mainshock (striking west-northwest and southeast, respectively) may have been triggered by this earthquake. The Coulomb stress change imparted by the rupture of these segments...

The Lembang Fault is located about eight km north of Bandung City, the capital city of the West Java province of Indonesia, with about 8.79 million people (dated 2020). Several studies state that the Lembang fault is an active fault with a maximum magnitude of 6.5 to 7. In terms of earthquake disaster mitigation, distinguishing characteristics of seismic velocity structures around active faults is critical. This manuscript presents our new research on ambient seismic noise tomography around the Lembang Fault by deploying 73 local temporary seismometer networks to develop a 3D high-resolution shear wave velocity model. We conducted a design acquisition analysis to obtain optimal results using a ray density analysis approach to image the geometry of the Lembang fault with good illumination and resolution, which is essential for identifying shallow geological features. Our result showed that variations in velocity values, both laterally and vertically, were related to variations in the...

Recent borehole seismic deployments conducted along the Baribis Fault in northwestern Java reveal that it may be active. In this study, we exploit these data to locate proximal earthquakes using a relative relocation technique, estimate their moment magnitudes using a spectral fitting method and compute their focal mechanisms via waveform inversion. We observe that seismicity in the eastern part of the fault is significantly higher than in the west, where a previous GPS study of the region south of Jakarta demonstrated the existence of high compression rates. These observations imply that the western Baribis Fault is locked, and that neighbouring areas, including southern Jakarta and its surroundings, may be highly vulnerable to future sizeable earthquakes when accumulated elastic strain energy is eventually released during fault rupture. Significantly, the current generation of Indonesia’s national hazard maps have not considered seismicity along the Baribis Fault. Our new results ...

The 2019 Mw 7.0 Banten, Indonesia, earthquake occurred at a 49 km depth in a relatively unknown region, where the geological structure did not clearly show the fault. In this study, we use the Global Navigation Satellite System data to analyse the fault source of the earthquake. Following the earthquake’s focal mechanism, we modelled a total of four fault models using two possible fault strikes, with each of the fault strikes investigated for shallow top depth and deeper top depth. This study also utilises the tide gauge data to confirm the tsunami waveform, modelled using the estimated coseismic slip. We present evidence of the shallow rupture of the 2019 Mw 7.0 Banten, Indonesia, intraslab earthquake from an ENE-WSW fault direction. The tsunami modelling of a shallow top depth of an ENE-WSW fault direction is a better fit in predicting the tide gauge waveform. We also present evidence that the 2019 Banten intraslab earthquake generated very few aftershocks for a magnitude 7-class ...

High seismicity rates in and around West Java occur as a result of the Indo-Australian plate converging with and subducting beneath the Sunda plate. Large megathrust events associated with this process likely pose a major earthquake and tsunami hazard to the surrounding community, but further effort is required to help understand both the likelihood and frequency of such events. With this in mind, we exploit catalog and phase data sourced from the Agency for Meteorology, Climatology, and Geophysics (BMKG) of Indonesia and the International Seismological Centre (ISC) for the period of April 2009 through July 2020, in order to conduct earthquake hypocenter relocation using a teleseismic double-difference method. Our results reveal a seismic gap to the south of West Java, which is in agreement with a previous GPS study that finds the same region to be a potential future source of megathrust earthquakes. Tsunami modeling was conducted in the region based on two scenarios using sources f...

Lombok is one of the islands in the transitional zone from the Sunda Arc to the Banda Arc, Indonesia. In the mid-2018, the island of Lombok was shaken by a series of strong earthquakes, started with a magnitude 6.4 earthquake on July 29, 2018 followed by earthquakes on August 5 (M 7.0), August 9 (M 5.9), and August 19 (M 6.3 and 6.9). Some researchers suggested that this phenomenon occurred due to a segmentation rupture in the northern part of Lombok Island. This study aims to obtain information on the distribution of the Lombok earthquake rupture zone 2018, through Shear Wave Splitting (SWS) study. Splitting, or S-wave separation, occurs when the S-wave passes through an anisotropic medium. The S wave is split into fast and slow S waves with almost orthogonal polarizations and has parameters such as delay time and polarization direction of the fast S wave. To determine the SWS parameters, we used a Lombok earthquake aftershock data set recorded from 4 August to 9 September 2018, us...

We use two‐plane‐wave tomography with a dense network of seismic stations across Sabah, northern Borneo, to image the shear wave velocity structure of the crust and upper mantle. Our model is used to estimate crustal thickness and the depth of the lithosphere‐asthenosphere boundary (LAB) beneath the region. Calculated crustal thickness ranges between 25 and 55 km and suggests extension in a NW‐SE direction, presumably due to back‐arc processes associated with subduction of the Celebes Sea. We estimate the β‐factor to be 1.3–2, well below the initiation of seafloor spreading. The LAB is, on average, at a depth of 100 km, which is inconsistent with models that ascribe Neogene uplift to wholescale removal of the mantle lithosphere. Instead, beneath a region of Plio‐Pleistocene volcanism in the southeast, we image a region 50–100 km across where the lithosphere has thinned to &lt;50 km, supporting recent suggestions of lower lithospheric removal through a Rayleigh‐Taylor instability.

The geological setting of Jakarta and its immediate surroundings are poorly understood, yet it is one of the few places in Indonesia that is impacted by earthquakes from both the Java subduction zone and active faults on land. In this study, a borehole seismic experiment with low noise characteristics was deployed to record seismic activity on the ~ E-W oriented Baribis Fault, which is ~ 130 km long, passes to the south of Jakarta, and is only ~ 20 km away at its nearest point. A primary objective of this study is to determine whether this fault is seismically active, and therefore, whether it might pose a threat to nearby population centers, including Jakarta in particular. A total of seven broadband instruments that spanned Jakarta and the surrounding region were installed between the end of July 2019 and August 2020, during which time we were able to detect and locate 91 earthquakes. Two earthquakes were located close to the Baribis Fault line, one of which was felt in Bekasi (so...

• New dataset produces finite frequency P wave tomographic model with unparalleled resolution of young arc-continent collision in Indonesia. • This model resolves a continuous slab that is deformed near the boundary between continental and oceanic crust but not torn. • This implies deep continental subduction prior to slab tearing and the localization of deformation along compositional boundaries.

We present here an analysis of the destructive Mw 6.2 earthquake sequence that took place on 14 January 2021 in Mamuju–Majene, West Sulawesi, Indonesia. Our relocated foreshocks, mainshock, and aftershocks and their focal mechanisms show that they occurred on two different fault planes, in which the foreshock perturbed the stress state of a nearby fault segment, causing the fault plane to subsequently rupture. The mainshock had relatively few aftershocks, an observation that is likely related to the kinematics of the fault rupture, which is relatively small in size and of short duration, thus indicating a high stress-drop earthquake rupture. The Coulomb stress change shows that areas to the northwest and southeast of the mainshock have increased stress, consistent with the observation that most aftershocks are in the northwest.