sperm whale clicks directionality and source level revisited in sperm whales physeter catodon l 1758 the nose is vastly hypertrophied accounting for about one third of the length or weight of an adult male norris and harvey in animal orientation and navigation nasa sp 262 1972 pp 397 417 ascribed a sound generating function to this organ complex a sound generator weighing upward of 10 tons and with a cross section of 1 m is expected to generate high intensity directional sounds this prediction from the norris and harvey theory is not supported by published data for sperm whale clicks source levels of 180 db re 1 pa and little if any directionality either the theory is not borne out or the data is not representative for the capabilities of the sound generating mechanism to increase the amount of relevant data a five hydrophone array suspended from three platforms separated by 1 km and linked by radio was deployed at the slope of the continental shelf off andenes norway in the summers of 1997 and 1998 with this system source levels up to 223 db re 1 pa perms were recorded also source level differences of 35 db for the same click at different directions were seen which are interpreted as evidence for high directionality this implicates sonar as a possible function of the clicks thus previously published properties of sperm whale clicks underestimate the capabilities of the sound generator and therefore cannot falsify the norris and harvey theory

bone preservation in kebara cave israel using on site fourier transform infrared spectrometry abstract the distribution of bones in kebara cave israel is very heterogeneous in order to address the question of whether the bone concentrations were created secondarily by differential dissolution or represent the original burial distributions a portable fourier transform infrared spectrometer ftir was operated on site it was used to map the distribution of the minerals in the sediments in order to delineate the zone in which original ash derived calcite was preserved as well as the zone in which carbonate apatite dahllite was still preserved the bone distribution in the former zone must be primary as calcite is less stable than dahllite the mineral phase of bone the boundary between the zone containing dahllite in the sediments and the zone in which it was absent also essentially mapped the southernmost distribution of bones in the cave the distribution of bones in the dahllite zone is thus also likely to be original supporting this notion was the observation that the bones at the periphery of the concentrations were not less well preserved than those in the centre except at one location which coincided with the boundary of the dahllite zone in the third zone the bones appear to have been lost by dissolution the operation of an ftir on site proved to be an efficient and useful method for resolving this important archaeological problem

modeling the microwave emission of bubbly ice applications to blue ice and superimposed ice in the antarctic and arctic passive microwave remote sensing is extensively used in polar regions to study the cryosphere to better understand the measured signal above continental ice covered areas our objective is to estimate the microwave emission of bubbly ice surfaces using a physically based multilayer electromagnetic model i e the dense media radiative transfer multilayer model dmrt ml this model accounts for ice layers with variable amounts of bubbles each layer is fully described by its temperature density thickness and air bubble radius simulations are performed using in situ data from two distinct sites one in antarctica on a coastal blue ice area near the cap prud homme cph station in adelie land and the other on the barnes ice cap bic located on baffin island in the arctic on this ice cap superimposed ice with seasonal snow cover about 1 m thick was observed in both cases several ice parameters were measured or estimated and the others were optimized results of the dmrt ml simulations are compared with in situ surface based radiometer sbr measurements at 11 19 and 37 ghz at both horizontal and vertical polarizations results show that dmrt ml is able to reproduce the microwave emission of different ice types with good accuracy when accounting for ice bubbles final hbox rmse 7 37 hbox k and 8 42 k for cph and bic respectively compared with rmse ranging from 15 k to 40 k without bubbles comparisons between sbr measurements and satellite data for the bic also show good agreement hbox rmse 4 1 hbox k for 19 and 37 ghz both polarizations

off axis effects on the multipulse structure of sperm whale usual clicks with implications for sound production sperm whales physeter macrocephalus produce multipulsed clicks with their hypertrophied nasal complex the currently accepted view of the sound generation process is based on the click structure measured directly in front of or behind the whale where regular interpulse intervals ipis are found between successive pulses in the click most sperm whales however are recorded with the whale in an unknown orientation with respect to the hydrophone where the multipulse structure and the ipi do not conform to a regular pulse pattern by combining far field recordings of usual clicks with acoustic and orientation information measured by a tag on the clicking whale we analyzed clicks from known aspects to the whale we show that a geometric model based on the bent horn theory for sound production can explain the varying off axis multipulse structure some of the sound energy that is reflected off the frontal sac radiates directly into the water creating an intermediate pulse p1 2 seen in off axis recordings the powerful p1 sonar pulse exits the front of the junk as predicted by the bent horn model showing that the junk of the sperm whale nasal complex is both anatomically and functionally homologous to the melon of smaller toothed whales

measuring snow and glacier ice properties from satellite satellite remote sensing is a convenient tool for studying snow and glacier ice allowing us to conduct research over large and otherwise inaccessible areas this paper reviews various methods for measuring snow and glacier ice properties with satellite remote sensing these methods have been improving with the use of new satellite sensors like the synthetic aperture radar sar during the last decade leading to the development of new and powerful methods such as sar interferometry for glacier velocity digital elevation model generation of ice sheets or snow cover mapping some methods still try to overcome the limitations of present sensors but future satellites will have much increased capability for example the ability to measure the whole optical spectrum or sar sensors with multiple polarization or frequencies among the methods presented are the satellite derived determination of surface albedo snow extent snow volume snow grain size surface temperature glacier facies glacier velocities glacier extent and ice sheet topography in this review emphasis is put on the principles and theory of each satellite remote sensing method an extensive list of references with an emphasis on studies from the 1990s allows the reader to delve into specific topics

spatial organization of middle paleolithic occupation x in kebara cave israel concentrations of animal bones abstract this paper examines the spatial distribution of faunal remains on the floor of kebara cave israel during unit x 60 000 3500 years one of the densest occupation layers in the site s late middle paleolithic sequence during unit x the central floor area of the cave contained numerous hearths and associated ash lenses surrounded by an area that was nearly devoid of macroscopic faunal remains except for three densely packed oval to circular concentrations of bones structures 1 2 and 3 each of which was surrounded by a dark organic rich aureole or ring and whose shape size and spatial location remain virtually unchanged during the accumulation of over 60 cm of unit x deposits mineralogical analyses of the sediments from the decapage surface using on site fourier transform infrared ftir spectrometry showed that the absence of visible bones outside of the three dense concentrations is not an artifact of differential preservation bones were also densely concentrated in a midden along the north wall of the cave adjacent to the occupation area the composition of the faunal assemblage from structure 1 the best preserved of the three structures is compared with the remains found in the midden and the results of these comparisons used as a basis for hypothesizing how these curious bone concentrations may have formed while no explanation can be offered with any degree of certainty one viable possibility is that these structures are the remains of trash filled pits further studies are suggested that may help clarify the nature of these unusual bone concentrations

looking for sharp edges modes of flint recycling at middle pleistocene qesem cave israel qesem cave is a middle pleistocene site in israel assigned to the acheulo yabrudian cultural complex aycc the cave reveals a suite of innovative behaviors including intensive flint recycling activities in this paper we present a new classification system developed for the study of lithic recycling at qesem cave through the careful technological analysis of hundreds of recycled items we have identified several recycling modes at qesem cave including a specific production trajectory of blades and knives recycled from old flakes we argue that the study of lithic recycling provides a significant glance at human decision making processes and the technological repertoire of the late lower paleolithic which are particularly pronounced when practiced within a lithic economy that enjoyed abundance rather than scarcity of stone our observations provide a more coherent view of aycc lithic recycling which might be applied to the study of lithic recycling in other paleolithic contexts

spatial aspects as seen from a density analysis of lithics at middle pleistocene qesem cave preliminary results and observations abstract this paper focuses on the results of a preliminary study of flint items densities in different areas and different parts of the stratigrapahic column of qesem cave qesem cave is a karst chamber cave with a 10 m stratigraphic sequence assigned to the acheulo yabrudian cultural complex aycc of the late lower paleolithic in the levant dated to 420 200 ka we first show the range of lithic densities in studied assemblages in the cave emphasizing significant differences in both the total number of lithic items per volume unit and or for selected artifact categories within these assemblages the results are used to suggest differential intensity of lithic related activities in the cave and variability in synchronic different areas of the cave within a similar stratigraphic level distribution aspects of lithic categories of selected assemblages we briefly note on the diachronic assemblages belonging to different parts of the stratigraphic sequence aspect of lithic densities in the discussion yet this aspect is not is not central in this paper a comparison of densities to frequency compositions of selected techno typological categories in the same assemblages areas further emphasizes the importance of using more than one quantitative measure as a descriptor of lithic assemblages and the interpretative potential of the interplay between the two measures in some analyzed aspects the differences between the two measures in the same assemblage are quite significant enabling interpretation of activity areas and specific human behaviors eventually further research testing lithic densities against and or incorporating them with other sets of density and frequency data from the same areas e g faunal remains or relating these densities to natural such as a rock shelf or human made features such as a fireplace may offer an elaborate and valuable landscape for reconstructing human behavior at the cave furthermore the spatial distribution of specific techno typological lithic categories within the assemblages studied as seen in densities augmented by available functional data derived from use wear analysis enable another perspective on the subdivision of activity areas in some parts of the sequence one synchronic example of our preliminary results which we present relates to generally contemporaneous assemblages adjacent to a constructed fireplace in the center of the cave in the upper part of the lower stratigraphic sequence dated to ca 300 ka both blade dominated amudian and quina and demi quina scrapers dominated yabrudian assemblages are involved indicating spatially differentiated functionally related differences around the fireplace

three dimensional beam pattern of regular sperm whale clicks confirms bent horn hypothesis the three dimensional beam pattern of a sperm whale physeter macrocephalus tagged in the ligurian sea was derived using data on regular clicks from the tag and from hydrophones towed behind a ship circling the tagged whale the tag defined the orientation of the whale while sightings and beamformer data were used to locate the whale with respect to the ship the existence of a narrow forward directed p1 beam with source levels exceeding 210 db peak re 1 pa at 1 m is confirmed a modeled forward beam pattern that matches clicks 20 off axis predicts a directivity index of 26 7 db and source levels of up to 229 db peak re 1 pa at 1 m a broader backward directed beam is produced by the p0 pulse with source levels near 200 db peak re 1 pa at 1 m and a directivity index of 7 4 db a low frequency component with source levels near 190 db peak re 1 pa at 1 m is generated at the onset of the p0 pulse by air resonance the results support the bent horn model of sound production in sperm whales while the sperm whale nose appears primarily adapted to produce an intense forward directed sonar signal less directional click components convey information to conspecifics and give rise to echoes from the seafloor and the surface which may be useful for orientation during dives

snow stratigraphic heterogeneity within ground based passive microwave radiometer footprints implications for emission modeling two dimensional measurements of snowpack properties stratigraphic layering density grain size and temperature were used as inputs to the multilayer helsinki university of technology hut microwave emission model at a centimeter scale horizontal resolution across a 4 5 m transect of ground based passive microwave radiometer footprints near churchill manitoba canada snowpack stratigraphy was complex between six and eight layers with only three layers extending continuously throughout the length of the transect distributions of one dimensional simulations accurately representing complex stratigraphic layering were evaluated using measured brightness temperatures large biases 36 to 68 k between simulated and measured brightness temperatures were minimized 0 5 to 0 6 k within measurement accuracy through application of grain scaling factors 2 6 to 5 3 at different combinations of frequencies polarizations and model extinction coefficients grain scaling factors compensated for uncertainty relating optical specific surface area to hut effective grain size inputs and quantified relative differences in scattering and absorption properties of various extinction coefficients the hut model required accurate representation of ice lenses particularly at horizontal polarization and large grain scaling factors highlighted the need to consider microstructure beyond the size of individual grains as variability of extinction coefficients was strongly influenced by the proportion of large hoar grains in a vertical profile it is important to consider simulations from distributions of one dimensional profiles rather than single profiles especially in sub arctic snowpacks where stratigraphic variability can be high model sensitivity experiments suggested that the level of error in field measurements and the new methodological framework used to apply them in a snow emission model were satisfactory layer amalgamation showed that a three layer representation of snowpack stratigraphy reduced the bias of a one layer representation by about 50

relation between eurasian snow cover snow depth and the indian summer monsoon an observational study abstract satellite derived snow cover data for 22 yr and snow depth data for 9 yr over eurasia have been analyzed to reexamine the possible relation of snow with the indian summer monsoon in contrast to the previous studies that use snow cover averaged over all of eurasia as a single number the frequency of occurrence of snow at each grid point over eurasia is correlated with the indian summer monsoon rainfall thus specific geographical regions over eurasia that are responsible for the well known inverse relationship between eurasian snow cover and indian monsoon rainfall are delineated it is found somewhat surprisingly that western eurasia is the only geographical region for which a significant inverse correlation exists between winter snow cover and subsequent summer monsoon rainfall however composites for high and low snow cover over eurasia show spatially homogeneous large scale patterns of snow cover and surface temperature anomalies winters of high and low snow cover for eurasia are found t

assessment of the relative accuracy of hemispheric scale snow cover maps there are several hemispheric scale satellite derived snow cover maps available but none has been fully validated for the period october 23 december 25 2000 we compare snow maps of north america derived from the moderate resolution imaging spectroradiometer modis and the national oceanic and atmospheric administration noaa national operational hydrologic remote sensing center nohrsc which both rely on satellite data from the visible and near infrared parts of the spectrum we also compare modis and defense meteorological satellite program dmsp special sensor microwave imager ssm i passive microwave snow maps the maps derived from visible and near infrared data are more accurate for mapping snow cover than are the passive microwave derived maps however discrepancies exist as to the location and extent of the snow cover among those maps the large approx 30 km footprint of the ssm i data and the difficulty in distinguishing wet and shallow snow from wet or snow free ground reveal differences up to 5 32 million sq km in the amount of snow mapped using modis versus ssm i data algorithms that utilize both visible and passive microwave data which would take advantage of the all weather mapping ability of the passive microwave data will be refined following the launch of the advanced microwave scanning radiometer amsr in the fall of 2001

the monopulsed nature of sperm whale clicks traditionally sperm whale clicks have been described as multipulsed long duration nondirectional signals of moderate intensity and with a spectrum peaking below 10 khz such properties are counterindicative of a sonar function and quite different from the properties of dolphin sonar clicks here data are presented suggesting that the traditional view of sperm whale clicks is incomplete and derived from off axis recordings of a highly directional source a limited number of assumed on axis clicks were recorded and found to be essentially monopulsed clicks with durations of 100 micros with a composite directionality index of 27 db with source levels up to 236 db re 1 micropa rms and with centroid frequencies of 15 khz such clicks meet the requirements for long range biosonar purposes data were obtained with a large aperture gps synchronized array in july 2000 in the bleik canyon off vesteralen norway 69 degrees 28 n 15 degrees 40 e a total of 14 h of sound recordings was collected from five to ten independent simultaneously operating recording units the sound levels measured make sperm whale clicks by far the loudest of sounds recorded from any biological source on axis click properties support previous work proposing the nose of sperm whales to operate as a generator of sound

combustion structures of archaeological level o and mousterian activity areas with use of fire at the abric romani rockshelter ne iberian peninsula abstract the human use of fire generates a cultural sedimentary record that can be used to characterize prehistoric activity areas the aim of this paper is to develop a field guide for recognizing and describing combustion structures the use of fire as suggested by the results of ethnoarchaeological and prehistoric archaeological studies has served as the foundation for the analytical design of the field observations of the combustion structures at the abric romani rockshelter flat and concave combustion structure types have been uncovered in archaeological level o the systematic recording of the sedimentary and dimensional attributes of the combustion structures can be used as empirical evidence with which to characterize the use of fire differences in the use of fire represent a significant finding in the cultural repertoires of neanderthals recognizing and recording the specific organizational patterns of these activity areas such as fire use in sleeping and resting activity areas indicate the definitive emergence of home bases in the spatial record of the living floors of the archaic human groups

off axis effects on the multi pulse structure of sperm whale coda clicks sperm whale physeter macrocephalus clicks have a multi pulse structure a result of the reflection of sound energy between air sacs in the spermaceti organ although previous research revealed that usual clicks used for echolocation recorded away from a vocalizing whale s longitudinal axis have waveforms with poorly defined pulse structures it has been unknown whether sperm whale coda clicks used for communication show similar off axis effects to address this knowledge gap a hydrophone array was used to localize vocalizing sperm whales and the waveforms of coda clicks recorded from different aspects were examined coda clicks recorded close to the whale s acoustic axis showed well defined multi pulsed waveforms while those recorded off axis did not as for usual clicks this suggests that sound energy radiates directly into the water upon reflection off the frontal sac

diagenesis in prehistoric caves the use of minerals that form in situ to assess the completeness of the archaeological record an interpretation of the archaeological record in particular that of a prehistoric cave site is complicated by the diversity of depositional and post depositional processes that affect the material deposited here we propose to use the authigenic minerals that form in situ within the cave sediments to reconstruct the ancient chemical environments in the sediments this can be done by experimentally determining the conditions under which each of the authigenic minerals are stable although this information is not available to date for minerals formed in a prehistoric cave we present calculated stability field data for the relevant minerals the results clearly demonstrate the feasibility of this approach this information particularly if based on measurements of real authigenic cave minerals will facilitate an assessment of the completeness of the cave archaeological record this is particularly important for determining whether or not the distributions of archaeologically important materials such as bones teeth plant phytoliths charcoal and ash reflect their original burial distributions or were altered as a result of secondary diagenetic processes

detection of the depth hoar layer in the snow pack of the arctic coastal plain of alaska u s a using satellite data interpretation de l epaisseur et de la localisation de la couche de givre dans le manteau neigeux a partir des donnees de la temperature de brillance de nimbus 7 37 ghz du smmr

a large aperture array of nonlinked receivers for acoustic positioning of biological sound sources a system of independent recording units that can be used to form an arbitrarily large acoustic array is described position of units and timing of signals are obtained from global positioning system gps with precisions within 2 5 m and 50 microseconds respectively an integrated hardware and software solution is presented and results reported from a four unit feasibility test in shallow water sound sources at a distance of 2 km were located within 2 to 138 m of gps derived positions