Deep Sounding Research Articles

The evolution of caprine herding in the hyper-arid zone of the southern Levant viewed through Niche Construction Theory

Caprine herding in the hyper-arid zone of the Southern Levant emerged in the early Holocene during a brief moist episode (∼9500 years ago) within semi-permanent Middle PPNB settlements that depended on herding, farming, and hunting/foraging, organized within a transhumant land use strategy. With the onset of much drier conditions (∼9200 years ago) these Desert Neolithic settlements were abandoned in Late PPNB times giving way to Timnian groups that followed a more mobile settlement strategy with an emphasis on herding accompanied by range expansion. Through introducing a case study of the Desert Neolithic site of Ayn Abū Nukhayla and a deep sounding in a nearby dry lake bed, climatic-environmental fluctuations, human demographics, resource availability and land use strategies are evaluated as interwoven effects relative to the progressive shifts seen between prehistoric human populations and caprine herds. And these changes are viewed in the context of cultural macroevolutionary theory, specifically in the framework of Niche Construction Theory (NCT), in weighing the differential influences of human agency and natural selection on the process.

A marine isotope stage 13 Acheulian sequence from the Amanzi Springs Area 2 Deep Sounding excavation, Eastern Cape, South Africa

Renewed research at Amanzi Springs has increased resolution on the timing and technology of the Acheulian industry in South Africa. The archeology from the Area 1 spring eye has recently been dated to MIS 11 (∼404–390 ka), and analyses revealed significant technological variability when compared to other southern African Acheulian assemblages. We expand on these results in presenting new luminescence dating and technological analyses of Acheulian stone tools from three artifact-bearing surfaces exposed within the White Sands unit of the Deep Sounding excavation in the Area 2 spring eye. The two lowest surfaces (Surfaces 3 and 2) are sealed within the White Sands and dated between ∼534 to 496 ka and ∼496 to 481 ka (MIS 13), respectively. Surface 1 represents materials deflated onto an erosional surface that cut the upper part of the White Sands (∼481 ka; late MIS 13), which occurred before the deposition of younger Cutting 5 sediments (<408–<290 ka; MIS 11–8). Archaeological comparisons reveal that the older Surface 3 and 2 assemblages are predominated by unifacial and bifacial core reduction and relatively thick, cobble-reduced large cutting tools. In contrast, the younger Surface 1 assemblage is characterized by discoidal core reduction and thinner large cutting tools, mostly made from flake blanks. Typological similarities between the older Area 2 White Sands and younger Area 1 (404–390 ka; MIS 11) assemblages further suggest long-term continuity in site function. We hypothesize Amanzi Springs represent a workshop locality that Acheulian hominins repeatedly visited to access unique floral, faunal, and raw material resources from at least ∼534 to 390 ka.

Наблюдения обратного сейсмоэлектрического эффекта II рода при электрозондированиях в районе Центрально-Сахалинского разлома

The results of experiments on electrical sounding of the near-surface layer of the Earth's crust in the fault zone, which have involved a recording of seismoacoustic and seismic noise in the close zone near the source (the primary dipole source), are represented. The experiments were carried out in 2021-2022 in the southern part of the Central Sakhalin fault with the use of the generator of electric pulses developed at IMGG FEB RAS, output electric power being up to 3 kW. The aim was to reveal seismoacoustic signatures of the medium reaction to the soundings with current pulses of 5–13 A. The generator provided significantly higher current in the dipole than its typical characteristics in the case of soundings for electrical exploration by resistance methods, as well as in the case of conventional seismic and electrical exploration. At the same time, the range of current amplitudes was much smaller in comparison with the case of a deep sounding based on application of geophysical MHD generators or other extra high-power electric pulses units. Up to now, the inverse seismoelectric effect has remained practically unexplored at currents in the “intermediate” range of ~10 A and scale lengths of the order of few hundreds of meters. The presence or absence of the medium reaction to electrical soundings was distinguished by the records of molecular-electronic sensors developed by R-sensors LLC: the CME-6111 broadband seismometer and the hydrophone, installed at a distance of about 50 m from one of the poles of the electric dipole source. An increase in the average level of seismoacoustic noise during electrical soundings was revealed, which is essentially a variety of the inverse seismoelectric effect of the second kind (excitation of elastic waves during an electric current run in a two-phase medium). Previously, no similar signature of medium reaction to the current pulses was noted in the close zone adjacent to one of the dipole electrodes. The noise level increase occurs almost without delay after the start of electrical soundings, and this is in accordance with the previously obtained results on the responses of seismic acoustic emission to powerful current pulses, which were used for a deep sounding in the Northern Tien Shan.

Ordinary Lydians at Home: The Lydian Trenches of the House of Bronzes and Pactolus Cliff at Sardis. By Andrew Ramage, Nancy H. Ramage, and R. Gül Gürtekin-Demir (SardisRep 8). 2 vols. Cambridge, Mass.: Archaeological Exploration of Sardis 2021. Pp. 570. $100. ISBN 9780674248557 (cloth).

<i>Ordinary Lydians at Home: The Lydian Trenches of the House of Bronzes and Pactolus Cliff at Sardis</i>. By Andrew Ramage, Nancy H. Ramage, and R. Gül Gürtekin-Demir (<i>SardisRep</i> 8). 2 vols. Cambridge, Mass.: Archaeological Exploration of Sardis 2021. Pp. 570. $100. ISBN 9780674248557 (cloth).

VIBROSEISMIC INVESTIGATIONS OF THE BAIKAL RIFT ZONE WITH A POWERFUL CVO-100 VIBRATOR

The article provides an overview of vibroseismic studies carried out in the Baikal rift zone using LargeScale Research Facilities – a powerful CVO-100 seismic vibrator, installed at the South Baikal geodynamic test site SB RAS. Research is carried out according to several methods focused on different tasks: study of the structure of the Earth’s crust and upper mantle in the BRZ, active vibroseismic monitoring, and verification of velocity models of the Earth’s crust. To study the structure of the Earth’s crust and the upper mantle, there were done the vibrator-generated wavefield recordings at the stationary regional network of seismic stations in the Buryat and Baikal branches of the Federal Research Center of the GS RAS, as well as the experimental studies involving the mobile networks deployment (ICMMG SB RAS, SIPE RAS, GIN SB RAS). The aim of the work is to carry out deep vibroseismic sounding of the Earth’s crust (vibro-DSS) at the junction of the Siberian platform, the BRZ and the Sayan-Baikal folded area. The methodology is based on the study of vibration seismograms with the determination of arrival times of the main groups of waves and their correlation with the velocity models of the Earth’s crust in the BRZ. A CVO-100 vibrator and a regional network of seismic stations are used to carry out active vibroseismic monitoring of the southern part of the BRZ. The active monitoring area is about 500×200 km. During vibroseismic monitoring, there were done thorough studies of seasonal variations of the vibrator-generated wavefield and the development of techniques for spectral correction of seismograms. A seismic vibrator CVO-100 was used to carry out experimental verification of the velocity models of the Earth’s crust, developed based on the BEST and PASSCAL experimental data. The vibrational deep seismic sounding (vibro-DSS) on the Baikal – Ulan Bator profile was carried out by the ICMMG SB RAS, GIN SB RAS and BB FRC GS RAS (Russia) in cooperation with IAG MAN (Mongolia).

Multiparameter approach in the deep geoelectrics

The main provisions of geoelectrics are described, the importance of taking into account the ambiguity of its inverse problem is emphasized. Three main methods of deep geoelectrics which use natural fields of ionospheric-magnetospheric origin are considered: geomagnetic deep sounding (GDS), magnetotelluric sounding (MTS), and magnetovariational profiling (MVP). The response functions of each method are described. Each response function carries its own specific information about some parameters of the studied object and is characterized by the degree of reliability of the information about the object extracted from it. For example, the most reliable information about electrical conductivity anomalies (if any in the study area) is contained in the MVP response functions. The horizontal tensor of the anomalous field contains information about the electrical conductivity under the observation point, and the tipper (induction vector) contains information from the surrounding areas. In general, MVP information is less susceptible to distortions than MTS information and deserves more trust. Artificial field sources in deep geoelectrics are rarely used due to their high cost. Since 1970, two powerful sources created for other purposes arised on the Kola Peninsula and were used for deep sounding. In the center of these studies found themself young talented geologist-geophysicist and organizer of major projects AbdulkhaiAzimovichZhamaletdinov. The «Khibiny» project with an MHD generator and an ultra-deep well as one of the objects of the study, the «Zeus» low-frequency emitter, the signals of which were recorded in China at a distance of 7000 km, and a number of projects conceived and organized by Zhamaletdinov and executed under his leadership: «Volgograd-Donbass» (1979, 1986), experiments «PHOENIX» (2007, 2009, 2014, 2019) and others. At the same time, methods of interpretation were developed for sounding with artificial EM sources and new response functions were obtained which make it possible to «see» the object of research in a new way. This experience must be preserved, generalized, improved and used, for example as follows. In the area of modern synchronous multipoint MTS-MVP survey, a controlled source composed of two grounded lines emits strong current (harmonics at fixed frequencies and/or pulses) which signal will be recorded by survey instruments during night-time sessions.

Shallow Structure of the Crust in the Sulu‐Dabie Region, China and its Seismotectonic Implication

AbstractThe P‐wave velocity structure in the shallow crust is investigated in and around the Sulu‐Dabie region by using seismic reflection data for deep soundings in 48 survey profiles and from rock velocity determinations. The observed velocity distributions show obvious heterogeneities in this region. The low velocity anomalies are observed mainly in the west of the Dabie region and the East Sea regions. The high velocity anomalies emerge in the shallow crust of the Sulu and Dabie orogeny. These high‐velocity anomalies can be attributed to the ultra‐high pressure metamorphosed (UHPM) rock formed by exhumation motion of mantle materials during the orogeny. The high‐velocity anomalies in the different shallow layers beneath the Sulu region are located to the northeast of the Tan‐Lu fault. The high‐velocity anomalies beneath the Dabie region are located southwest of the Tan‐Lu fault. Such a distribution pattern of velocity anomaly zones may reveal historical motion of a left‐lateral strike‐slip for the Tan‐Lu fault, which differs from the result of a right‐lateral strike‐slip motion regime known from modern seismology, indicating a more complex tectonic motion along the Tan‐Lu fault.

Fiftieth Anniversary of the Kola SG-3 Superdeep Borehole

The results of a comprehensive study of electrical properties of the upper part of the Earth’s crust according to the data of lateral resistivity logging of the Kola SG-3 superdeep borehole and the results of deep and superdeep sounding using controlled sources and electrical profiling on the daylight surface are presented. The possibility of extrapolation of the Kola SG-3 temperature field to a depth below the bottomhole, up to the Moho discontinuity, taking into account the data MHD sounding with the Khibiny source and with the use of industrial power transmission lines (FENICS experiment) is considered. The results of frequency electromagnetic soundings with controlled sources are analyzed, and their geodynamic interpretation is performed together with the data of drilling the SG-3 borehole. The geological and geophysical data are interpreted in the Kola SG-3 section and on the daylight surface to search for homologs and define the nature of the intermediate conductive layer of the dilatancy-diffusion nature (DD layer) discovered in the Earth’s crust of the Baltic Shield at depths from 2–3 to 7–8 km. Based on the latest results of remote deep sounding (the Murman-2018 experiment), it is concluded that, in the vicinity of Kola SG-3 at a depth of 10–12 km, there is a boundary of “impenetrability” for direct current (for the galvanic mode). The geodynamic interpretation of the data is carried out taking into account the model by V.N. Nikolaevskii (1996); it has been suggested that the new boundary most closely corresponds to the brittle-to-quasi-plastic transition area of the Earth’s crust. The results are compared to the log data of the SG-3 borehole and the data of superdeep drilling.

Symmetrical and Asymmetrical Rectifications Employed for Deeper Ocean Extrapolations of In Situ CTD Data and Subsequent Sound Speed Profiles

The multinational Argo program, which was initiated in 1999, has completed its global requirement of 3000 floats deployed by 2007. This program has revolutionized ocean observations with the provision of varying data in the upper half of the ocean. However, various studies have reiterated the requirement for deep ocean coverage, since the ocean below 2000 meters (m) is warming. In this regard, full-depth studies are mandatory in order to estimate the rising sea level due to thermal expansion and analyze critical parameters of deep ocean circulation sub 2000 m; further, data below 2000 m are mandatory for multifarious model simulations. As a landmark initiative, in mid-2015, the “Deep Argo Implementation Workshop” was held in Hobart. An array comprising 1228 floats was suggested by G. C. Johnson, rendering coverage of 5° latitude × 5° longitude × 15-day cycles. This was conclusively agreed to be an affordable solution for varying scientific needs for assessing data in abyssal oceans. Thence, Deep New profilINg float of JApan (NINJA) and Deep Arvor floats were developed by Japan and France, respectively, to cover depths of 0–4000 m. Similarly, Deep Autonomous Profiling Explorer (APEX) and Deep Sounding Oceanographic Lagrangian Observer (SOLO) by the United States were designed to cover 0–6000 m. The data offered by this underdeveloped deep pilot array are scarce on both temporal and spatial scales. This particular study offers an ingenious and novel approach to extrapolating conductivity–temperature–depth (CTD) profiles, as well as sound speed profiles (SSPs), in abyssal oceans below 2000 m. The primitive results of this method exhibited certain discrepancies which were subsequently rectified by modifying the aforementioned method both symmetrically and asymmetrically in an innovative way. The final outcomes of this method are almost identical to the in situ values obtained from Deep Argo floats, and in this way, offer a way to compute deep ocean calculations both spatially and temporally since Deep Argo floats are aimed at relatively sparse deployments and require a longer duration to provide data (5° latitude × 5° longitude × 15-day cycles) as compared to Core Argo data (3° latitude × 3° longitude × 10-day cycles). The SSP computations were conducted by employing multiple equations such as Chen and Millero, Del Grosso, and UNESCO (United Nations Educational, Scientific, and Cultural Organization) algorithms. The study concludes by offering transmission loss rectifications by employing the aforementioned method as a future course of action.

Processing and Interpreting the Data of Deep Frequency Sounding in a Complex with Audiomagnetotelluric Measurements (Murman-2018 Experiment)

This paper aims to study the deep electrical conductivity of the Murmansk block (Fennoscandian Shield) using the controlled source audio-frequency magnetotelluric (CSAMT) and audiomagnetotelluric (AMT) methods. One of the most important tasks in deep sounding studies implying the joint application of the AMT and CSAMT methods is to take into account the influence of surface conductors on the measurement results (static shift). To solve this problem, we develop a methodology for processing and interpreting the measurement data of the CSAMT and AMT system using the results of the deep sounding experiment conducted in the frequency range from 1 to 500 Hz performed in 2018 (Murman-2018) as an example. Measurements with the controlled source in the form of two mutually orthogonal horizontal electric dipoles are taken at distances of 12 to 105 km. The generator-measuring complex consisted of the VMTU-10 measuring station (manufactured by OOO VEGA, St. Petersburg) and the Energy-4 generator (developed at the Kola Science Center, Russian Academy of Sciences, Apatity). Using the synchronous time series of the field components at the observation points and the current in the supply dipole, the power spectra of the autocorrelation and cross-correlation functions of the recorded values are calculated based on the fast Fourier transform (FFT). The obtained spectral characteristics are used (i) to determine the amplitudes of the source field’s components and the phase shifts between them, and (ii) to evaluate the components of the AMT field’s impedance tensor. The values of the apparent resistivity are calculated using the amplitudes of the horizontal components of the electromagnetic field and the impedance ratios. The obtained measurement results are corrected for the static shift. For this, the correction coefficients are calculated from the ratio between the apparent resistivity values for the horizontal component of the magnetic field and the apparent resistivity values inferred from the impedance and electrical field values. The data for the cases of axial and equatorial arrays, together with the data of the AMT and remote sounding, made it possible to establish a high degree of lateral homogeneity of the deep electrical section and to expand the frequency range of the obtained curves of the apparent resistivity and impedance phase. A one-dimensional interpretation is made to obtain estimates of the distribution of the deep resistivity.

The Bug mining area of the Ukrainian shield. Structural-petrophysical map of the crystalline basement and some problems of the Early Precambrian geology

Structural and petrophysical map of a scale 1:100 000 of the Bug mining area (BMA), one of the most promising areas of ore minerals in the eastern part of the Ukrainian shield has been built. The area is located in the Middle Bug (sheets of topographic map M-35-XXXVI-eastern half and M-36-XXXI). Materials of geological survey of a scale 1:50 000, deep geological mapping of a scale 1:200 000, exploration, as well as: geophysical surveys of a scale 1:10 000—1:50 000, seismic and geoelectric deep sounding; special tectonic works on outcrops; published results of determining the isotopic age of Precambrian rocks have been put into the basis of the constructions.Authors tried to enclose only indisputable data such as material composition, structural and textural features, petrophysical characteristics of rocks, the contours and dimensions of bodies by geophysical data and drilling, tectonophysical parameters of discontinuous structures directly in the map content.Unclear and discussion debatable points on the map are not shown and discussed in the text. These problems include the tectonic position of BMA (the Bug Mining Area), which, according to the authors, belonged to the Bug megablock in the Archean and in the Proterozoic it was divided by the fault Talnov zone and as a result of the process of shifting-pulling apart its eastern part joined the Ingul megablock. The deep crust-mantle nature established in the territory of BMA of the large Golovanevsk and Bandurivka gravitation anomalies have been shown.The authors rejected the division of Early Precambrian rocks of granulite facies into suites as because the principle of a sequence of strata and correlation of sections in the area is not observed. The problem of the scope of the Dniester and Bug series from which rocks of Proterozoic kinzigite formations were excluded is being discussed here. Particular attention has been paid to the mechanisms of formation of subvertical layered banded structure of thickness of Early Precambrian granulite complexes of the area. It is shown that this structurally textured rock fabric formed in the early Proterozoic as a result of horizontal forces and horizontal movements of the substance and the folding has mainly near-fault shift character with subvertical hinges of folds, which is clearly seen in the horizontal sections and by the results of drilling.

Detecting fingerprints of audio steganography software

Steganography has experienced rapidly growth with spreading access to the Internet in recent decades. Such low cost, simple process and easy promotion steganographic softwares pose serious and growing threats and challenges to network security. The fingerprint of steganography has proven itself an effective solution. However, large gaps exist between experiments results and practical applications. Few attention has been paid on the fingerprint of steganography. In this paper, we provide highly effective solutions to identify the fingerprints of audio steganography. Based on the analysis of audio stego produced by three kinds of audio steganographic softwares, including Xiao Steganography, Invisible Secrets, Deep Sound, we successfully detect audio stego across WAV files. Besides, we summarize a general approach of fingerprint extraction, and its effectiveness has been confirmed through experiments. The results solve an urgent need for further research on reverse engineering steganography softwares and detecting audio stego.

Groundwater exploration in a typical southwestern basement terrain

ABSTRACT Integrated geophysical techniques were applied for groundwater exploration in a typical southwestern Nigeria basement terrain. EM-3D was primarily used to map out the precise subsurface conductive zones before adopting the recommended sounding locations with aid of Vertical Electrical Sounding (VES) technique. Hydraulic parameters were also estimated and plotted. Twenty Electromagnetic (EM) horizontal profiling and Schlumberger methods were conducted in E-W and N-S direction across the site. The points where the inflection of the raw real intersects the positive peak of the filtered real are diagnostic of major conductive zones suspected to be faults/fractures. Possible groundwater flow paths that identified as conductive zones were used in picking locations for VES deep sounding. The VES conducted on the conductive zones, which are labelled V1, V2, V3 and V4 were characterised by good aquifer resistivity values with relatively thick overburden, which are the major factors in determining the groundwater potential of an area in a typical basement complex, while those carried out on the non-conductive zones labelled V5 and V6 were characterised by poor indication to groundwater potential of the area.

On geoacoustic inversions, sediment acoustics, and deep ocean ambient noise

During the period of 2005–2011, three topics in acoustical oceanography were actively investigated in the Buckingham Lab which combined field, lab, and theoretical work. Geoacoustic inversions in the low frequency (&amp;lt;500 Hz) band were carried out using the noise generated by a light aircraft off the coast of La Jolla, California, and during the MAKAI experiment in Kauai, Hawaii. The inversion relied on a comparison of data to an analytical model of a moving airborne source over a two-layer shallow water waveguide. In an effort to investigate the link between grain roughness and porosity to support the development of a theory of acoustic propagation in sediments, a statistical model for the two-dimensional shape of sand grains was developed from the digitized outlines of grains from a dozen locations, including deserts, beaches, and seabeds. Lastly, a family of autonomous free-falling ambient noise profilers known as Deep Sound, were designed, manufactured, and deployed, returning measurements of ambient noise from below the critical (or reciprocal) depth in the deep ocean. Field experiments were carried out in the San Diego trough, the Philippine Sea, the Tonga Trench, and the Sirena Deep and Challenger Deep in the Mariana Trench.

Estimation of the Geoacoustic Properties of the New England Mud Patch From the Vertical Coherence of the Ambient Noise in the Water Column

The autonomous passive-acoustic lander Deep Sound was deployed at five locations during the Office of Naval Research (ONR)-supported Seabed Characterization Experiment, a multi-institutional field effort held at the New England Mud Patch, where the seabed is known to consist of a thick layer of silt and clay overlying a medium and coarse sand. The five deployments of Deep Sound were up to 9 h long, during which time ambient noise data, taken over an acoustic bandwidth of 5 Hz–30 kHz, were collected on four hydrophones arranged in an inverted “T” shape. Local temperature and conductivity were also recorded continuously at each location. A wave number integral model of wind-driven noise in a fluid waveguide over a two-layered elastic seabed was used to calculate the dependence of the vertical noise coherence on the geoacoustic properties in the overlying silt and clay layer, as well as the subbottom sand half-space. The modeled noise coherence was fitted to the data over the band 100 Hz–12 kHz, returning the compressional- and shear-wave speeds and densities of both layers and the thickness of the top layer.

Effect of Ionosphere and Inhomogeneity of the Earth Structure on the Polarization Characteristics of Magnetic Field at Frequencies of 0.2–200 Hz in the Near-Field Zone of a Horizontal Grounded Antenna

Polarization characteristics of the field of an on-Earth emitter located at the Kola Peninsula are experimentally measured at a distance that is no greater than the height of an effective ionospheric waveguide in the FENICS-2014 experiment. Variations in the field amplitude and orientation of the major axis of polarization ellipse are observed at lower frequencies upon significant changes of the K index of geomagnetic activity. Polarization characteristics of the horizontal component of magnetic field calculated with allowance for the ionosphere and two-layer Earth structure prove the observed sensitivity of the ultralow- and lower-frequency filed in the near-field zone to the state of ionosphere at lower conductivity of underlying medium. Theoretical results are compared with the experimental data. The results are important for deep sounding of the Earth and monitoring of ionosphere with the aid of controlled low-frequency ground sources.

Refined models of the conductivity distribution at the transition from the Bohemian Massif to the West Carpathians using stochastic MCMC thin sheet inversion of the geomagnetic induction data

Although volume 3D modeling solutions has become widespread in recent time, thin sheet approximation of Earth's conductivity distribution can still serve as a useful tool when quasi-3D conductivity structures in the heterogeneous subsurface are investigated and the available database of observations is limited to long-period electromagnetic induction data from large-scale deep sounding arrays. We present results of stochastic Monte Carlo-Markov Chains MCMC inversion of long-period induction arrows based on the Bayesian statistics strategy. We concentrated on the different methodological aspects of MCMC for Gibbs sampling and for adaptive Metropolis algorithm together with convergence of these methods. The results are presented on a case study from the transition zone between the Bohemian Massif and the West Carpathians where a phantom effect caused by superposition of the prominent SW-NE trending Carpathian Conductivity Anomaly and NW-SE trending anomalous structure related to the fault system at the eastern boundary of the Bohemian Massif appears.

한신·아와지대지진(阪神淡路大震災)의 문학화와 전쟁 기억: 오다 마코토(小田実)의 『깊은 소리(深い音)』를 중심으로

한신·아와지대지진(阪神淡路大震災)의 문학화와 전쟁 기억: 오다 마코토(小田実)의 『깊은 소리(深い音)』를 중심으로

Temporal perspectives on Still Bay point production at Sibudu Cave, KwaZulu-Natal, in the context of southern Africa

ABSTRACTBased on optically stimulated luminescence age estimates it has been argued that the Still Bay represents a sudden, short-lived technological innovation dating to about 72–71 kya. Yet, few sites have the stratigraphic integrity and Still Bay point assemblage size to test this assumption. The Wadley deep sounding of Sibudu Cave provides such an opportunity. Here we use fine-grained analyses consisting of technological attributes and morphometric data to explore the retouched point assemblages of Sibudu over a period of more than ten thousand years spanning the Still Bay. Although we found subtle changes through time, we found no evidence of a technological break in retouched point-production strategies since the Wadley early pre-Still Bay at more than 77 kya through to the final Still Bay/early Howiesons Poort dating to 64.7 ± 2.3 kya. We did, however, uncover a potential point-production hiatus at the site and we present testable hypotheses for this phenomenon. We further contextualise the Sibudu assemblages within southern Africa by directly comparing them with those of Hollow Rock Shelter, Umhlatuzana and Apollo 11. Although our results demonstrate both variation and similarities between the different Still Bay assemblages, we could not replicate a previous suggestion regarding technical disconnection between a north-east/south-west axis on the greater landscape.

The benefits of prenatal singing for mother and infant

Prenatal singing promotes wellbeing during pregnancy thanks to the physical and vocal exercises involved. The songs can serve as a tool for expressing feelings and emotions and favour communication between the mother and infant. The voice's deep sounds, particularly natural during childbirth, are combined with breathing and create vibrations which support the woman during contractions. Doing the exercises again after the birth help her to regain a feeling of bodily fulfilment.