Deep Sounding Research Articles

The Cyrenaican Prehistory Project 2009: the third season of investigations of the Haua Fteah cave and its landscape, and further results from the 2007–2008 fieldwork

AbstractThe paper reports on the third (2009) season of fieldwork of the Cyrenaican Prehistory Project, and on further results from the analysis of materials collected in the previous (2007 and 2008) fieldwork. Sediments in a 14 m-deep core drilled beside the McBurney trench provide an invaluable overview of the overall stratigraphic sequence, including at depths reached by the 1950s Deep Sounding but not yet investigated by the present project. Sampling of newly-exposed faces of the original excavation trench for dating (14C, ESR, OSL, U-series) and palaeoenvirommental indicators continued. Excavation was begun of sediments assigned to the early Holocene Libyco-Capsian (McBurney's Layer X), and of Pre-Aurignacian layers beside the top of the Deep Sounding. The Libyco-Capsian layers are particularly prolific in lithic debris, shells, and animal bones; preliminary analysis of the lithics suggests a development from Typical to Upper Capsian within the layers excavated in 2009. Geoarchaeological survey along the littoral to the west and east of the Haua Fteah identified complex sequences spanning most of the last interglacial-glacial cycle. Geoarchaeological survey south of the Haua Fteah characterized the major landforms of the Gebel Akhdar mountain and of the pre-desert and desert-edge zones further south, with Late Stone Age (Upper Palaeolithic and Epipalaeolithic) material being found especially on the southern side of the Gebel Akhdar, and Middle Stone Age (Middle Palaeolithic) material in the pre-desert and desert regions. The first suite of14C dates (from charcoal samples taken in 2007) indicates the use of the Haua Fteah by Oranian hunter-gatherers during the Last Glacial Maximum and in the succeeding millennia, but not in the Younger Dryas cold/dry phase (c. 11,000–10,000 cal. BC), with Libyco-Capsian occupation resuming soon after the beginning of the Holocenec. 9000 cal. BC, suggesting that the cave, and perhaps the Gebel Akhdar in general, have a complex history as refugia for human settlement during the Pleistocene.

Structural electrical anisotropy in the crust at the South-Central Chilean continental margin as inferred from geomagnetic transfer functions

Induction vectors, as a visualization of geomagnetic deep sounding transfer functions, display an unique pattern at the South Chilean continental margin between latitudes 38°–41°S and longitudes 71°–74°W: at long periods of approx. 3000s their real parts are uniformly deflected from the W–E direction (which would be expected due to the coast effect and/or anomalies beneath the roughly N–S striking Andean mountain chain) to the NE. Attempts to model this behavior with simple and geologically realistic 3-D models failed, but a reasonable data fit was obtained by employing 2-D models with a structurally anisotropic, lower crust. This anisotropy hints at a deeply fractured, fluid-rich crust with a major strike direction of 40°–50° (SW–NE), oblique to the continental margin and in accordance with the regional stress field in the region of the volcanic arc. A surprising result is that the anisotropy persists in the forearc and may even reach until the continental slope near the trench.

Vertical profiling of ambient noise with Deep Sound.

Deep Sound is a free‐falling high‐bandwidth acoustic recording system designed to profile ambient noise from the surface to depths of 9 km. The recording platform is autonomous and descends under gravity to its preprogramed maximum depth, where a burn‐wire releases weight, permitting the system to return to the surface under its own buoyancy. Two hydrophones are mounted at half meter vertical spacing allowing the noise spectrum and vertical coherence (directionality) to be obtained over four decades of frequency (10 Hz–100 kHz). The acoustic recordings are made continuously as the instrument descends and ascends along with measurements of sound speed and depth. The system's low power and large data storage capabilities allow round trips to the deepest trenches of the ocean. Alternative modes of operation include (1) synthetic aperture signal detection and (2) residence on the seabed with return to the surface at a later time. Deep Sound's design and acoustic characteristics will be described and data from...

Bademağacı Kazıları 2004, 2005 ve 2006 Yılları Çalışma Raporu

Bademağacı Höyüğü'nde 1993'de başlayan kazıların son üç yıldaki çalışmaları, sırası ile 5 Ağustos - 16 Eylül 2004, 30 Temmuz - 14 Eylül 2005 ve 28 Temmuz - 14 Eylül 2006 tarihleri arasında sürdürüldü(1). Bu raporumuzda, çalışmaların sonuçları bir arada sunulmaktadır(2).

Interpretation of the deep magnetotelluric soundings along the Austrian part of the CELEBRATION-007 profile

In the continuation of the CELEBRATION-007 deep seismic profile from Hungary to Austria a series of deep magnetotelluric soundings has been carried out, using the instruments (from GFZ MT instrument pool). In spite of the high noise level, the relatively good imaging of the structure of the sedimentary Graz Basin and possibly fluid filled conducting fractures in the resistive rock matrix of the Eastern Alps have been indicated. They might be potential source of geodynamics (earthquakes?).

Airborne VLF measurements and mapping of ground conductivity in Sweden

Airborne VLF data are routinely collected by The Geological Survey of Sweden (SGU) as part of its bedrock mapping programme. In this paper we demonstrate that the novel Tensor VLF technique developed at Uppsala University and SGU can provide useful qualitative and quantitative information about the electrical conductivity distribution in the upper few hundred meters. Single transmitter scalar VLF maps emphasize those conductive structures that have dominant strikes in the direction of the transmitter. The tensor tipper (essentially the vertical magnetic field from currents along the strike direction) calculated from multiple transmitters is dependent only upon the underlying conductivity structure. Transformation of the tipper into the peaker (the horizontal divergence) has proven to enhance the lateral resolution while the transformation to the apparent resistivity can be used to discriminate different rock types. Two case histories from the application of VLF data are presented in this study. Two dimensional structures can be quantitatively modelled by modern inversion methods developed originally for deep electromagnetic MT soundings. Direct inversion of the real and imaginary parts of the tipper provides more quantitative information about the subsurface resistivity distribution.

The configuration of the fresh–saline groundwater interface within the regional Judea Group carbonate aquifer in northern Israel between the Mediterranean and the Dead Sea base levels as delineated by deep geoelectromagnetic soundings

A combined high resolution short offset transient electromagnetic (SHOTEM) and deep sounding, long offset (LOTEM) survey has been carried out along two traverses between the Mediterranean Sea and the Jordan-Dead Sea Rift (DSR). The DSR is located in the study area some 200–250 m below sea level. The measurements detected a deep conductor, the top of which exhibited a regular behavior along the both traverses, declining from the Mediterranean to the DSR base level. The geometry of this geoelectric boundary coincides fairly well with the configuration of a supposed fresh/saline groundwater interface as also obtained by both numerical and physical modeling for the known hydrogeological conditions in the study area. Therefore the detected geoelectric boundary is identified with the interface, supporting the hypothesis of current seawater intrusion into the deep regional aquifers between the Mediterranean and the DSR base levels. The intrusion causes the salination of fresh groundwater within the aquifers as well as the salination of the Sea of Galilee.

A new approach to gradient geomagnetic sounding

A spherical model of the Earth including a heterogeneous upper mantle and excited by the magnetic field of a magnetospheric ring current is constructed. The obtained synthetic data are used for testing a new approach to gradient geomagnetic sounding ensuring the immunity of the sought impedance to distortions caused by lateral heterogeneity of the Earth. It is shown that this approach significantly increases the informativeness of deep electromagnetic sounding.

The Politics of Knowledge in Premodern Islam

This is an excellent book. With a beautiful, exemplary scholarly style, OmidSafi treats the reader to a deep sounding of accounts of the frequently marginalizedplayers and problems of Islamicate intellectual, religious, political, and social history. The welcome news is that we must learn to treat nothingas marginal in the formation of culture and thought. The audiences andconversations analyzed and interpreted here provide a previously largelyunnoticed door to some very serious truths about the rise, formation, andespecially the characteristic institutional formations of early and later medievalIslamicate society. While I think the title is a mistake (premodern producesinappropriate expectations), one is equally sympathetic with theauthor’s avoidance of the “M” word for a number of reasons. One of themost pernicious of these is that medieval frequently functions as a euphemismfor Islamic or Islamicate in a milieu still disinclined to appreciate theformative, creative, and enduring genius of this great civilization and thedebt that our world so profoundly owes it. Forgive the khutbah, but it seemsthat this cannot be repeated too often, unfortunately ...

Deep sounding with industrial power lines in conjunction with MTS measurements

This study is devoted to the development of a method for deep tensor electromagnetic inductive sounding of the Baltic Shield lithosphere with the use of mutually orthogonal industrial power lines alternately connected to a generator of up to 100 kW in power. The first results of the sounding are obtained at separations of up to 510 km from the source. The electrical conductivity of the Baltic Shield lithosphere in the crust-mantle transition zone (depths of 20–50 km) is numerically estimated from soundings with natural and controlled sources. The perspectives of future investigations are associated with synchronous observations on a 2-D network of measuring stations. This will enable the study of the relation of deep geoelectric parameters of the lithosphere to the geological structure of the crust in terms of 3-D models.

The electric field in northern England and southern Scotland: implications for geomagnetically induced currents

SUMMARY Magnetotelluric (MT) data, in the form of MT tensors, are used to estimate directly the size and spatial distribution of the electric field in northern England and southern Scotland with the aim of predicting the flow of geomagnetically induced currents (GIC) in power networks in the region. MT and Geomagnetic Deep Sounding data from a number of different field campaigns, at a period of 750 s, are employed. The MT data are cast in the form of telluric vectors, which allow a joint hypothetical event analysis (HEA) of both Geomagnetic Deep Sounding and MT data. This analysis reveals qualitatively the pervasive effects of electric field distortion in the region. Two approaches are taken to understand how the spatial structure of the regional electromagnetic field is affected by local distortions, and what the origin of these distortions might be. The dimensionality, and form of electric field distortion, of the MT tensors is investigated using the Weaver et al. and Bahr classification schemes, and by examining the misfit of a galvanic distortion model as a function of rotation angle. At sites where the galvanic distortion model is found to be appropriate the regional MT tensors are recovered using tensor decomposition techniques. It is found that recovering the regional MT response reconciles the geometry of induced currents implied by the MT data with that of the Magnetic Variation anomalies. Lilley’s central impedances are used to calculate rotationally invariant effective telluric responses. In the Southern Uplands the magnitude of the effective telluric response is approximately 0.25-0.5 mV km −1 nT −1 , but as the Southern Uplands Fault is approached it rises steadily to 3 mV km −1 nT −1 . In the Midland Valley, the effective telluric response is approximately 0.5 mV km −1 nT −1 which rises steadily to 2.5 mV km −1 nT −1 as the Southern Uplands and Highland Boundary Faults are approached to the southeast and northwest, respectively. Therefore, the increase in the magnitude of the effective telluric response correlates with the approach of a major tectonic boundary such as the Southern Uplands Fault. These results show that the induced electric field strength varies considerably throughout the central Scotland region. In addition, the HEA indicates that due to lateral changes in conductivity structure the direction of the electric field deviates significantly from the regional direction implied by the polarization azimuth of the primary geomagnetic induction. Therefore, any attempts to model the flow of GIC in the region need to account for the spatial variation of both the magnitude and azimuth of the electric field.

A review of the resistivity structure of the Karoo Supergroup, South Africa, with emphasis on the dolerites: A study in anisotropy

The resistivity structure of the Karoo Basin has been determined by an extensive programme of some 280 deep electrical soundings (maximum current electrode spacing = 40 km). The very conductive carbon and pyrite- rich Whitehill Formation acts as an electrical basement to deep soundings where it is well developed. Beyond its limit in the east, the electrical basement consists of granites and metamorphic rocks and is highly resistive. Notwithstanding an appreciable difference in resistivity between the sandstone and mudstone components, the sandstones are neither sufficiently massive nor continuous to be detected separately in sounding curves. Exceptions are a few, thick, massive arenaceous turbidite fans occurring under an appreciable cover in the downwarped Karoo Trough, straddling the Lower Beaufort and Upper Ecca Subgroups at the southern extremity of the basin. The average resistivity of the sedimentary pile above the Whitehill Formation increases from north to south by more than an order of magnitude substantiating geological evidence of a sympathetic increase in diagenesis and metamorphosis. The Karoo Supergroup comprises one of the rare instances of a sedimentary basin where dolerite intrusions occur interbedded with sediments. The very high resistivity contrast between the resistive dolerite and the conductive sediment, results in an exceptionally high degree of electrical anisotropy. This feature has provided a unique opportunity to study the configuration of the network of dolerite intrusions in the sedimentary succession but simultaneously has often seriously restricted the depth of investigation. Previous geological investigations have demonstrated a tri-zonal vertical variation in intrusive style. The resistivity study has shown that elements in each of these zones have their own specific geophysical signature. The largest portion of the basal zone 3 with its flat lying dolerite sills of great lateral extent is confined to well-laminated, homogeneous shales with a high degree of anisotropy in the Lower Ecca Subgroup and is characterized by a low transverse resistance on sounding curves corresponding to a concomitant low content of dolerite. The onset of zone 2, which coincides with the appearance of the first sandstones in the Waterford Formation, is accompanied by a dramatic increase in transverse resistance and hence the amount of dolerite. This dolerite-rich zone, which continues through the Beaufort Group and partially into the higher Formations is characterised by a multitude of basin structures. The variation in structure of the network of dolerites correlates with that of the nexus of lenticular sandstones intercalated with shales and mudstones. Detailed investigations, such as the one in the De Aar area, show that the average percentage of dolerite in the dolerite bearing layer of zone 2 is 45% with a high of 85% and a low of about 10%. Regionally, zone 2 thins to the south but thickens to the east by a factor of at least 5, at the expense of zone 3. The thickening is associated with a lateral increase in the amount of dolerite. Towards the upper portion of zone 2 there is a lower concentration of intrusions and a trend towards smaller basin structures in the Molteno, Elliot and Clarens Formations. Arguably, the most important contribution of the resistivity soundings is the conclusive finding that in the uppermost zone 1, which extends from the surface to a depth of about 700 m, the dominant style of intrusion is that of steeply dipping sheets and vertical dykes and that the zone is especially dolerite-poor with the amount of dolerite only making up about 0.5% or less of the sediments. The nature of zone 1 is independent of the lithology and is due to the decrease of overburden pressure.

Tectonic weak zones determined by magnetotellurics along the CEL-7 deep seismics profile

In the contact zone of three tectonic units (Pannonian Basin, Eastern Alps and Dinarides), in a complicated — basin and range — geological situation magnetotelluric deep soundings were carried out along a 140 km long profile (CELEBRATION-007) with a site distance of 2 km. In this area deep fractures of the Basin run together in NE-SW direction.

Effects of T-shape groin parameters on beach accretion

The effects of various groin parameters (length, head length and opening) and wave parameters (wave height, wave period and wave angle) on the accretion of the area protected by T-shape groins are studied in a physical model. The model studies are performed using regular waves in a basin. A numerical model which depends primarily on a CERC model is employed to examine the effects of some of the above parameters. Good agreement is found in the results of physical and numerical models. The results of a numerical model are compared with field data obtained by deep sounding measurements at Of coasts, Trabzon Province, Turkey. The finding from this study may be employed in designing T-shape groins.

The backs of some sealings from Nineveh 5

In 1930 to 1931, the British Museum expedition to Nineveh included among its activities there a stratigraphical sounding which resulted in the establishment of a sequence of prehistoric and early historic remains in northern Mesopotamia over a considerable chronological period (on the deep sounding of Nineveh see now Gut 1995; Gut 2002, esp. pp. 17–22, and also Gut 1999). This sequence, comprising five broadly defined phases, extends from the Neolithic (Ninevite 1) to the early third millennium BC (Ninevite 5).In 1989 I had the opportunity to study archaeological materials deposited in the British Museum in London. I was interested in the earliest Mesopotamian sealings — those of Tell Arpachiyah and Nineveh — and was provided not only with Ninevite 2–3 sealings which I had requested, but also with those of Ninevite 5, so I documented the latter as well. After publishing the Ninevite 2–3 items (Charvát 1994), I had no opportunity to publish the remainder.However, in 2001 Dominique Collon published an analysis of the seal impressions found in the Ninevite 5 archaeological strata documented by the Thompson and Mallowan expedition (Collon 2001; see also Collon 2003). When “Nineveh” was announced as the theme of the 49e Rencontre Assyriologique Internationale, I decided to present a paper on the detailed information I had recorded for a number of the backs of the sealings studied by Collon. My work builds upon Collon's art-historical analysis of the obverse of the sealings, but here I am concentrating on the “hidden faces” of the seal impressions in order to extend my study of the character of socially engineered exchange practices in the protohistorical period of early Mesopotamia.

Integrated deep drilling, coring, downhole logging, and data management in the Chicxulub Scientific Drilling Project (CSDP), Mexico

Abstract— Impact structures in the solar system are mainly recognized and explored through remote sensing and, on Earth, through geophysical deep sounding. To date, a continuous scientific sampling of large impact craters from cover rocks to target material has only seldom been performed. The first project to deep‐drill and core into one of the largest and well‐preserved terrestrial impact structures was executed in the winter of 2001/2002 in the 65 Myr‐old Chicxulub crater in Mexico using integrated coring sampling and in situ measurements. The combined use of different techniques allows a three‐dimensional insight and a better understanding of impact processes.Here, we report the integration of conventional rotary drilling techniques with wireline mining coring technology that was applied to drill the 1510 m‐deep Yaxcopoil‐1 (Yax‐1) well about 40 km southwest of Mérida, Yucatán, Mexico. During the course of the project, we recovered approximately 900 m of intact core samples including the transitions of reworked ejecta to post‐impact sediments, and that one from large blocks of tilted target material to impact‐generated rocks, i.e., impact melt breccias and suevites. Coring was complemented by wireline geophysical measurements to obtain a continuous set of in situ petrophysical data of the borehole walls. The data acquired is comprised of contents of a natural radioactive element, velocities of compressional sonic waves, and electrical resistivity values. All the digital data sets, including technical drilling parameters, initial scientific sample descriptions, and 360° core pictures, were distributed during the course of the operations via Internet and were stored in the ICDP Drilling Information System (http:www.icdp‐online.org), serving the global community of cooperating scientists as a basic information service.

Tectonic map and overall architecture of the Alpine orogen

The new tectonic map of the Alps is based on the combination of purely structural data with criteria regarding paleogeographical affiliation and/or tectono-metamorphic evolution. The orogenic evolution of the Alps is discussed using a combination of maps and paleogeographical reconstructions. It is proposed that the Alps are the product of two orogenies, a Cretaceous followed by a Tertiary one. While the former is related to the closure of an embayment of the Meliata ocean into Apulia, the latter is due to the closure of the Alpine Tethys between Apulia and Europe. The along-strike changes in the overall architecture, as for example revealed by geophysical-geological transects, are by far more substantial than hitherto believed. It appears that the Alps are still far from being over-investigated, as is demonstrated by many surprising recent findings based on field geology, laboratory results and geophysical methods of deep sounding.

A review of the nature and geophysical studies of the thick permafrost in Siberia: Relevance to exploration on Mars

In this paper we discuss the best Siberian permafrost analog of the Martian cryosphere in connection with the design of deep‐sounding geophysical methods for the detection of liquid water beneath frozen formations on Mars. The peculiarities of the terrestrial cryolithozone and its unique thickness (up to 1.5 km) in the region under consideration (Western Yakutia) are described. The Russian experience in detecting the lower boundary of permafrost, by various geophysical methods, and suggestions regarding the most effective methods for the deep sounding of the Martian cryosphere are also briefly discussed.

Nutrient cycling and fluxes in Beatrix Bay, Pelorus Sound, New Zealand

Nitrogen (N) and light availability limit phytoplankton growth and hence regulate food supply for mussel farming in Pelorus Sound, New Zealand. In Beatrix Bay, a large 35‐m deep embayment off Pelorus Sound, the supply of N is heavily influenced by physical factors. Bottom intrusions of N‐rich or depleted oceanic water occur in the main channel of Pelorus Sound and N‐depleted, phytoplankton‐enriched Pelorus River water characterises the near‐surface low salinity field. Inside Beatrix Bay, nutrient cycling via phytoplankton uptake, sedimentation, and subsequent regeneration from the sediments by mineralisation, also has an important influence on the availability of N in the water column. However, almost continuous salinity or thermally induced density stratification, or both, within Beatrix Bay meant that the upper and lower water columns were often decoupled so that N regenerated from the sediments was not readily available in the upper water column, and phytoplankton settling from the upper water column may not reach the sediments directly below because of large horizontal transport. The N supply in the upper water column of Beatrix Bay, where the mussels are farmed, is most likely regulated by advection in and out of the bay from external sources. Conversely, the N concentrations below the pycnocline could be almost entirely supplied via mineralisation from the sediments. The rates of sediment N regeneration were seasonally dependent. During winter, when sedimentation exceeds mineralisation, N accumulates in the sediments at a rate of up to 10 mg m–2 day–1, whereas in summer, when mineralisation exceeds sedimenation, N is lost from the sediments at rates of up to 9 mg m–2 day–1.

Apparent resistivity of azimuthal anisotropy layered media

The electric field, equations of boundary conditions and calculation formula of apparent resistivity are derived for azimuthal anisotropy layered media with DC method based on anisotropic Ohm’s law. Taking Schlumberger symmetric system as an example and using recurrence formula of nuclear function, the paper theoretically simulates a model of four layers with the same anisotropy coefficient for each layer. The deep sounding curves of resistivity and the pattern of contours are obtained for the model. The results shows the theoretical formula of this paper is correct, the deep sounding curves not only exhibit the difference of resistivity among layers but also indicate the anisotropy characteristics of layers.