the carbon stable isotope biogeochemistry of streams taylor valley antarctica abstract the mcmurdo dry valleys region of antarctica is the largest ice free region on the continent this study reports the first c stable isotope measurements for dissolved inorganic c present in ephemeral streams in four dry valleys that flow for four to twelve weeks during the austral summer one of these valleys taylor valley has been the focus of the mcmurdo dry valleys long term ecological research mcm lter program since 1993 within taylor valley numerous ephemeral streams deliver water to three perennially ice covered closed basin lakes lake fryxell lake hoare and lake bonney the onyx river in the wright valley the longest river in antarctica flows for 40 km from the wright lower glacier and lake brownworth at the foot of the glacier to lake vanda streamflow in the mcmurdo dry valley streams is produced primarily from glacial melt as there is no overland flow however hyporheic zone exchange can be a major hydrogeochemical process in these streams depending on landscape position these streams vary in gradient channel substrate biomass abundance and hyporheic zone extent this study sampled streams from taylor wright garwood and miers valleys and conducted diurnal sampling of two streams of different character in taylor valley in addition transect sampling was undertaken of the onyx river in wright valley the 13 c pdb values from these streams span a range of greater than 14 from 9 4 to 5 1 with the majority of samples falling between 3 and 2 suggesting that the c stable isotope composition of dissolved c in mcmurdo dry valley streams is largely inorganic in character because there are no vascular plants on this landscape and no groundwater input to these streams atmospheric exchange is the dominant control on 13 c dic

trackline and point detection probabilities for acoustic surveys of cuvier s and blainville s beaked whales acoustic survey methods can be used to estimate density and abundance using sounds produced by cetaceans and detected using hydrophones if the probability of detection can be estimated for passive acoustic surveys probability of detection at zero horizontal distance from a sensor commonly called g 0 depends on the temporal patterns of vocalizations methods to estimate g 0 are developed based on the assumption that a beaked whale will be detected if it is producing regular echolocation clicks directly under or above a hydrophone data from acoustic recording tags placed on two species of beaked whales cuvier s beaked whale ziphius cavirostris and blainville s beaked whale mesoplodon densirostris are used to directly estimate the percentage of time they produce echolocation clicks a model of vocal behavior for these species as a function of their diving behavior is applied to other types of dive data from time depth recorders and time depth transmitting satellite tags to indirectly determine g 0

direct observation of heavy metal mineral association from the clark fork river superfund complex implications for metal transport and bioavailability two sets of samples from riverbeds and adjacent floodplains separated by 80 river kilometers were collected from the clark fork river superfund complex montana the largest superfund site in the united states and studied primarily with transmission electron microscopy tem with several supporting techniques to determine heavy metal mineral association seven of the eight samples studied were strongly influenced by material that once resided in mining and smelting dumps and impoundments this material was transported downstream sometime during the last century and a half from the butte anaconda areas the eighth sample was from a deeper floodplain level and dates to premining days the tem observations afford a direct look down to the nanometer level at secondary mineral formation as a result of the breakdown of sulfides and silicates in the acid environment of this massive mine drainage system in the shallow oxic floodplain sediments heavy metals of concern in this system as cu pb and zn are taken up by the formation of sulfates particularly pb in jarosite as well as hydrous metal oxides as cu pb and zn in and on ferrihydrite and a possibly new vernadite like mineral the oxides are long lived in these systems as they were also found in the anoxic riverbeds metals are also taken up by the formation of sulfides in sulfate reducing environments as observed in the formation of nanoclusters of chalcopyrite and sphalerite in all samples clays make up between 5 and 20 of the sediment and carry significant amounts of cu and zn the hydrous oxides secondary sulfides and clays provide several routes for metal transport downstream over long distances besides the potential bioavailability of heavy metals exchanged on and off the hydrous metal oxides and clays nanometer sized sulfides may also be highly reactive in the presence of biologic systems

biological and geochemical controls on diel dissolved inorganic carbon cycling in a low order agricultural stream implications for reach scales and beyond abstract movement of dissolved inorganic carbon dic through the hydrologic cycle is an important component of global carbon budgets but there is considerable uncertainty about the controls of dic transmission from landscapes to streams and through river networks to the oceans in this study diel measurements of dic 13c dic dissolved oxygen o2 18o o2 alkalinity ph and other parameters were used to assess the relative magnitudes of biological and geochemical controls on dic cycling and flux in a nutrient rich net autotrophic stream rates of photosynthesis p respiration r groundwater discharge air water exchange of co2 and carbonate precipitation dissolution were quantified through a time stepping chemical isotope 12c and 13c 16o and 18o mass balance model groundwater was the major source of dic to the stream primary production and carbonate precipitation were equally important sinks for dic removed from the water column the stream was always super saturated with respect to carbonate minerals but carbonate precipitation occurred mainly during the day when p increased ph we estimated more than half possibly 90 of the carbonate precipitated during the day was retained in the reach under steady baseflow conditions the amount of dic removed from the overlying water through carbonate precipitation was similar to the amount of dic generated from r air water exchange of co2 was always from the stream to the atmosphere but was the smallest component of the dic budget overall the in stream dic reactions reduced the amount of co2 evasion and the downstream flux of groundwater derived dic by about half relative to a hypothetical scenario with groundwater discharge only other streams with similar characteristics are widely distributed in the major river basins of north america data from usgs water quality monitoring networks from the 1960s to the 1990s indicated that 40 of 652 stream monitoring stations in the contiguous usa were at or above the equilibrium saturation state for calcite and 77 of all stations exhibited apparent increases in saturation state from the 1960 70s to the 1980 90s diel processes including partially irreversible carbonate precipitation may affect net carbon fluxes from many such watersheds

the continuous re equilibration of carbon isotope compositions of hydrous mg carbonates in the presence of cyanobacteria abstract the hydrous magnesium carbonate minerals dypingite mg5 co3 4 oh 2 5h2o and nesquehonite mgco3 3h2o were precipitated in the presence and absence of gloeocapsa sp and synechococcus sp cyanobacteria in batch reactors the 13cmineral dic is similar in both biotic and abiotic systems stable carbon isotope analyses of the precipitated minerals and co existing fluids indicated that the 13c values of the precipitated carbonates co vary over time with the 13cdic of the fluid phase even after the precipitation of the carbonate is complete this observation indicates the continuous isotopic exchange between the carbonates and the fluid a process that efficiently resets the original 13c values of the solids therefore although cyanobacterial induced mg carbonates are 10 5 enriched in 13c compared to inorganic carbonates the 13c values of natural hydrous mg carbonates may reflect post precipitation processes and may not be reliable for paleo environmental reconstructions

depositional and halokinetic sequence stratigraphy of the neoproterozoic wonoka formation adjacent to patawarta allochthonous salt sheet central flinders ranges south australia parts of two third order neoproterozoic marinoan depositional sequences are documented in the wilpena group wonoka formation and bonney sandstone at patawarta diapir located in the central flinders ranges south australia these sequences represent an overall regressive succession transitioning upwards from outer to middle wave dominated shelf deposits to a tidally dominated barrier bar to coastal plain the lower middle upper limestone and green mudstone informal members of the wonoka formation comprise the highstand systems tract of the lower sequence the sequence boundary is at the top of the wonoka green mudstone member and is overlain by the lowstand systems tract of the upper sequence which includes the lower dolomite sandstone and upper dolomite beds of the patsy hill member of the bonney sandstone the upper sequence transgressive systems tract comprises thebonneysandstone theseunitscompriseonecompletetaperedcompositehalokineticsequence chs the lower halokinetic sequence boundary is associated with the maximum flooding surface of the lower depositional sequence and the upper halokinetic sequence boundary is interpreted as the transgressive surface of the overlying depositional sequence where an angular truncation of up to 908is documented the majority of our knowledge of salt tectonic processes is derived from the analysis of subsurface datasetsfromoffshorepetroleum bearingsaltbasins such as the gulf of mexico brazil west africa and

echolocation transmitting beam of the atlantic bottlenose dolphin the transmitting beam patterns of echolocation signals emitted by an atlantic bottlenose dolphin tursiops truncatus were measured in the vertical and horizontal planes with an array of seven hydrophones particular emphasis was placed on accurately verifying the animal s position on a bite plate tail rest stationing device using underwater video monitoring equipment the major axis of the vertical beam was directed at an angle of 5 above the plane defined by the animal s lips this angle was 15 lower than previously measured the vertical beam measurements indicate that the major axis of the transmitting beam is aligned with the major axis of the receiving beam the horizontal beam was directed forward the directivity index of 26 5 db calculated from the beam pattern measured in both planes agreed well with previous calculation of 25 4 db

assessment of diel chemical and isotopic techniques to investigate biogeochemical cycles in the upper klamath river oregon usa abstract the upper klamath river experiences a cyanobacterial algal bloom and poor water quality during the summer diel chemical and isotopic techniques have been employed in order to investigate the rates of biogeochemical processes four diel measurements of field parameters temperature ph dissolved oxygen concentrations and alkalinity and stable isotope compositions dissolved oxygen 18 o and dissolved inorganic carbon 13 c have been performed between june 2007 and august 2008 significant diel variations of ph dissolved oxygen do concentration and do 18 o were observed due to varying rates of primary productivity vs respiration vs gas exchange with air diel cycles are generally similar to those previously observed in river systems although there are also differences compared to previous studies in large part these different diel signatures are the result of the low turbulence of the upper klamath river observed changes in the diel signatures vs sampling date reflect the evolution of the status of the algal bloom over the course of the summer results indicate the potential utility of applying diel chemical and stable isotope techniques to investigate the rates of biogeochemical cycles in slow moving rivers lakes and reservoirs but also illustrate the increased complexity of stable isotope dynamics in these low turbulence systems compared to well mixed aquatic systems

diel behavior of stable isotopes of dissolved oxygen and dissolved inorganic carbon in rivers over a range of trophic conditions and in a mesocosm experiment abstract rates of diel 24 h biogeochemical processes in rivers and their effect on daily changes in the concentration of metals and metalloids have been well documented in the literature over the last 20 years investigations into the effects of these processes on aquatic systems and the underlying mechanisms that control the processes can significantly improve our understanding of how natural aquatic environments function and will respond to changing environmental conditions and anthropogenic impacts daily changes in the rates of biogeochemical processes have more recently been shown to influence the stable isotope composition of dissolved oxygen and dissolved inorganic carbon in natural waters here we present a comprehensive picture of the persistence and reproducibility of diel cycles of the 18o composition of dissolved molecular oxygen 18o do and the 13c composition of dissolved inorganic carbon 13c dic across five montana usa rivers investigated over a 4 year period a mesocosm experiment showed the same behavior in 18o do and 13c dic as seen in riverine settings across light and dark periods a cross plot of 18o do and 13c dic from each stream exhibits a clockwise elliptical pattern which is attributed to the daily changes in the balance of metabolic rates as well as air water gas exchange the amplitude of the change in the isotope composition is shown to be directly related to the trophic state of the river and a relationship between net productivity and diel changes in 18o do and 13c dic is presented this relationship between trophic status with 18o do 13c dic and production emphasizes the significance of how rates of biogeochemical processes in natural systems can influence the daily changes in the composition of surface waters

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

diel behavior of rare earth elements in a mountain stream with acidic to neutral ph abstract diel 24 h changes in concentrations of rare earth elements ree were investigated in fisher creek a mountain stream in montana that receives acid mine drainage in its headwaters three simultaneous 24 h samplings were conducted at an upstream station ph 3 3 an intermediate station ph 5 5 and a downstream station ph 6 8 the ree were found to behave conservatively at the two upstream stations at the downstream station ree partitioned into suspended particles to a degree that varied with the time of day and concentrations of dissolved ree were 2 9 to 9 4 fold 190 to 830 higher in the early morning vs the late afternoon the decrease in dissolved ree concentrations during the day coincided with a corresponding increase in the concentration of ree in suspended particles such that diel changes in the total ree concentrations were relatively minor 27 to 55 increase at night across the lanthanide series the heavy ree partitioned into the suspended solid phase to a greater extent than the light ree filtered samples from the downstream station showed a decrease in shale normalized ree concentration across the lanthanide series with positive anomalies at la and gd and a negative eu anomaly as the temperature of the creek increased in the afternoon the slope of the ree profile steepened and the magnitude of the anomalies increased the above observations are explained by cyclic adsorption of ree onto suspended particles of hydrous ferric and aluminum oxides hfo hao conditional partition coefficients for each ree between the suspended solids and the aqueous phase reached a maximum at 1700 hours and a minimum at 0700 hours this pattern is attributed to diel variations in stream temperature possibly reinforced by kinetic factors i e slower rates of reaction at night than during the day estimates of the enthalpy of adsorption of each ree onto suspended particles based on the field results averaged 82 kj mol and are similar in magnitude to estimates in the literature for adsorption of divalent metal cations onto clays and hydrous metal oxides the results of this study have important implications to the use of ree as hydrogeochemical tracers in streams

effective beam pattern of the blainville s beaked whale mesoplodon densirostris and implications for passive acoustic monitoring the presence of beaked whales in mass strandings coincident with navy maneuvers has prompted the development of methods to detect these cryptic animals blainville s beaked whales mesoplodon densirostris produce distinctive echolocation clicks during long foraging dives making passive acoustic detection a possibility however performance of passive acoustic monitoring depends upon the source level beam pattern and clicking behavior of the whales in this study clicks recorded from digital acoustic tags dtags attached to four m densirostris were linked to simultaneous recordings from an 82 hydrophone bottom mounted array to derive the source level and beam pattern of the clicks as steps towards estimating their detectability the mean estimated on axis apparent source level for the four whales was 201 dbrms97 the mean 3 db beamwidth and directivity index estimated from sequences of clicks directed towards the far field hydrophones were 13 and 23 db respectively while searching for prey blainville s beaked whales scan their heads horizontally at a mean rate of 3 6 s over an angular range of some 10 thus while the di indicates a narrow beam the area of ensonification over a complete foraging dive is large given the combined effects of body and head movements associated with foraging

estimating cetacean population density using fixed passive acoustic sensors an example with blainville s beaked whales methods are developed for estimating the size density of cetacean populations using data from a set of fixed passive acoustic sensors the methods convert the number of detected acoustic cues into animal density by accounting for i the probability of detecting cues ii the rate at which animals produce cues and iii the proportion of false positive detections additional information is often required for estimation of these quantities for example from an acoustic tag applied to a sample of animals methods are illustrated with a case study estimation of blainville s beaked whale density over a 6day period in spring 2005 using an 82 hydrophone wide baseline array located in the tongue of the ocean bahamas to estimate the required quantities additional data are used from digital acoustic tags attached to five whales over 21 deep dives where cues recorded on some of the dives are associated with those received on the fixed hydrophones estimated density was 25 3 or 22 5 animals 1000km2 depend

baird s beaked whale echolocation signals echolocation signals from baird s beaked whales were recorded during visual and acoustic shipboard surveys of cetaceans in the california current ecosystem and with autonomous long term recorders in the southern california bight the preliminary measurement of the visually validated baird s beaked whale echolocation signals from towed array data were used as a basis for identifying baird s signals in the autonomous recorder data two distinct signal types were found one being a beaked whale like frequency modulated fm pulse the other being a dolphin like broadband click the median fm inter pulse interval was 230 ms both signal types showed a consistent multi peak structure in their spectra with peaks at 9 16 25 and 40 khz depending on signal type as well as recording aspect and distance to the hydrophone these peaks varied in relative amplitude the description of baird s echolocation signals will allow for studies of their distribution and abundance using towed array data without associated

tracing dissolved o2 and dissolved inorganic carbon stable isotope dynamics in the nyack aquifer middle fork flathead river montana usa abstract the geochemistry and microbiology of shallow groundwater aquifers is greatly influenced by the concentration of dissolved oxygen gas do however the mechanisms that consume do in groundwater e g biotic or abiotic are often ambiguous the use of stable isotopes of molecular o 2 18 o do in conjunction with stable isotopes of dissolved inorganic carbon 13 c dic has potential to discriminate between the various mechanisms causing do depletion in subsurface waters here we report the results of spatial and seasonal changes in 18 o do and 13 c dic at the nyack floodplain aquifer along the middle fork of the flathead river near west glacier montana usa over a short well constrained flow path 100 m near a main recharge zone of the floodplain the 18 o do consistently increased as do concentrations decreased with distance from the recharge source concurrently dic concentrations increased and 13 c dic values decreased these observations are explained by community respiration coupled with dissolution of calcite from cobbles in the aquifer matrix when these results are compared to data from wells distributed over the entire floodplain several km a much less predictable relationship was observed between do concentration and 18 o do many wells with low do concentrations e g 1 or 4 mg l 1 had anomalously low 18 o do values e g 2 may be contributed to the aquifer by diffusion from the vadose zone and by advection from the river recharge calculations presented here suggest that diffusion across a narrow air water interface can contribute isotopically light 18 o do to the saturated zone possible contributions of light 18 o do from other processes such as isotopic exchange and radial oxygen loss from plant roots in or near the water table are compared and evaluated

three dimensional tracking of cuvier s beaked whales echolocation sounds using nested hydrophone arrays cuvier s beaked whales ziphius cavirostris were tracked using two volumetric small aperture 1 m element spacing hydrophone arrays embedded into a large aperture 1 km element spacing seafloor hydrophone array of five nodes this array design can reduce the minimum number of nodes that are needed to record the arrival of a strongly directional echolocation sound from 5 to 2 while providing enough time differences of arrivals for a three dimensional localization without depending on any additional information such as multipath arrivals to illustrate the capabilities of this technique six encounters of up to three cuvier s beaked whales were tracked over a two month recording period within an area of 20 km 2 in the southern california bight encounter periods ranged from 11 min to 33 min cuvier s beaked whales were found to reduce the time interval between echolocation clicks while alternating between two inter click interval regimes during their descent towards the seafloor maximum peak to peak source levels of 179 and 224 db re 1 pa 1 m were estimated for buzz sounds and on axis echolocation clicks directivity index 30 db respectively source energy spectra of the on axis clicks show significant frequency components between 70 and 90 khz in addition to their typically noted fm upsweep at 40 60 khz

classification of broadband echoes from prey of a foraging blainville s beaked whale blainville s beaked whales mesoplodon densirostris use broadband ultrasonic echolocation signals with a 10db bandwidth from 26to51khz to search for localize and approach prey that generally consist of mid water and deep water fishes and squid although it is well known that the spectral characteristics of broadband echoes from marine organisms vary as a function of size shape orientation and anatomical group there is little evidence as to whether or not free ranging toothed whales use spectral cues in discriminating between prey and nonprey in order to study the prey classification process a stereo acoustic tag was deployed on a blainville s beaked whale so that emitted clicks and the corresponding echoes from targets in the water could be recorded a comparison of echoes from targets apparently selected by the whale and those from a sample of scatterers that were not selected suggests that spectral features of the echoes target strengths or both may have been used by the whale to discrimina

the acoustic field on the forehead of echolocating atlantic bottlenose dolphins tursiops truncatus arrays of up to six broadband suction cup hydrophones were placed on the forehead of two bottlenose dolphins to determine the location where the beam axis emerges and to examine how signals in the acoustic near field relate to signals in the far field four different array geometries were used a linear one with hydrophones arranged along the midline of the forehead and two around the front of the melon at 1 4 and 4 2 cm above the rostrum insertion and one across the melon in certain locations not measured by other configurations the beam axis was found to be close to the midline of the melon approximately 5 4 cm above the rostrum insert for both animals the signal path coincided with the low density low velocity core of the melon however the data suggest that the signals are focused mainly by the air sacs slight asymmetry in the signals were found with higher amplitudes on the right side of the forehead although the signal waveform measured on the melon appeared distorted when they are mathematically summed in the far field taking into account the relative time of arrival of the signals the resultant waveform matched that measured by the hydrophone located at 1 m

description of sounds associated with sowerby s beaked whales mesoplodon bidens in the western north atlantic ocean several groups of sowerby s beaked whales mesoplodon bidens were encountered on july 4 2011 during a shipboard cetacean survey conducted off the eastern seaboard of the united states acoustic recordings were collected using a three element towed hydrophone array many echolocation clicks were recorded during the encounter but no tonal sounds were detected a total of 2969 echolocation clicks were included in analyses of frequency and temporal characteristics a gaussian mixture model with four mixtures was fitted to the histogram of peak frequencies four subsets of clicks were designated the majority of clicks n 2048 contained a median peak frequency of 33 khz while the others contained a median peak frequency of 25 khz n 324 51 khz n 304 or 67 khz n 293 most clicks did not contain a clear frequency modulated upsweep though some clicks exhibited a slight sweep from 30 36 khz seven burst pulses were detected in the encounter two of which were of high enough quality for detailed analysis the acoustic characteristics of sowerby s beaked whales have not previously been described the current study will facilitate incorporation of these data into passive acoustic monitoring programs in the north atlantic ocean

species identification and measurement of activity in odontocete species of palmyra atoll by acoustic monitoring acoustic monitoring has been used to study odontocete presence at palmyra atoll a remote island in the northern line islands chain long term recordings of high frequency broadband acoustic data have become possible with recent technological advances a high frequency autonomous recording package harp has been developed which samples at 200 khz with a duty cycle of 1 4 for up to seven months this instrument has recorded since october 2006 at palmyra atoll visual and acoustic surveys were conducted around palmyra atoll using a four element towed hydrophone array sampling real time at 200 khz to obtain species specific acoustic data these data are used as reference for automatic detection algorithms applied on the long term recordings to date acoustically and visually detected odontocetes include bottlenose dolphins tursiops truncatus spinner dolphins stenella longirostris melon headed whales peponocephala electra and beaked whales of the genus mesoplodon the long term harp data reveal acoustic activity primarily at night time and predominantely odontocete clicks both the beaked as well as the melon headed whales are present year round and show a distinct daily acoustic activity cycle

echolocation clicks of free ranging cuvier s beaked whales ziphius cavirostris strandings of beaked whales of the genera ziphius and mesoplodon have been reported to occur in conjunction with naval sonar use detection of the sounds from these elusive whales could reduce the risk of exposure but descriptions of their vocalizations are at best incomplete this paper reports quantitative characteristics of clicks from deep diving cuvier s beaked whales ziphius cavirostris using a unique data set two whales in the ligurian sea were simultaneously tagged with sound and orientation recording tags and the dive tracks were reconstructed allowing for derivation of the range and relative aspect between the clicking whales at depth the whales produced trains of regular echolocation clicks with mean interclick intervals of 0 43 s 0 09 and 0 40 s 0 07 the clicks are frequency modulated pulses with durations of 200 s and center frequencies around 42 khz 10 db bandwidths of 22 khz and q3 db of 4 the sound beam is narrow with an estimated directionality index of more than 25 db

the biosonar field around an atlantic bottlenose dolphin tursiops truncatus the use of remote autonomous passive acoustic recorders par to determine the distribution of dolphins at a given locations has become very popular some investigators are using echolocation clicks to gather information on the presence of dolphins and to identify species however in all of these cases the par probably recorded mainly off axis clicks even some from behind the animals yet there is a very poor understanding of the beam pattern and the click waveform and spectrum from different azimuths around the animal s body the beam pattern completely around an echo locating dolphin was measured at 16 different but equally spaced angles in the horizontal plane using an 8 hydrophone array in sequence eight channels of data were digitized simultaneously at a sampling rate of 500 khz the resulting beam patterns in both planes showed a continuous drop off in sound pressure with azimuth around the animal and reached levels below 50 db relative to the signal recorded on the beam axis the signals began

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

influence of diel biogeochemical cycles on carbonate equilibrium in a karst river abstract variations in temperature photosynthesis and respiration force diel variations in ph and dissolved co 2 concentrations of surface streams possibly controlling carbonate equilibrium between river water and carbonate stream beds diel cycles of water chemistry and 13 c of dissolved inorganic carbon dic were measured to assess how biogeochemical processes affect dissolution and precipitation of calcite and thus channel development in ichetucknee river a large spring fed river discharge 6 m 3 s flowing over carbonate karst terrain in north central florida usa samples were collected at a 4 h sampling interval during two one week periods and at a 1 h interval during a single 24 h period simultaneously temperature ph dissolved oxygen do and no 3 concentrations were measured using in situ sensors at 15 min or 1 h intervals ca 2 dic and no 3 concentrations decreased during the day and increased at night causing diel changes of in stream specific conductivity these changes were inversely related to diel changes in ph pco 2 and do concentrations this work shows that photosynthesis and respiration of subaquatic vegetation are the dominant processes influencing in stream diel variation during the day a simultaneous increase of 13 c dic and decrease in dic indicates that photosynthesis was the primary control on dic concentrations calcite saturation indices ranged from 0 to 0 5 with the highest value in daylight as a result of co 2 consumption causing carbonate precipitation the water remained saturated with respect to calcite at night and 13 c dic values decreased indicating that co 2 production from ecosystem respiration was the dominant process affecting dic concentrations but was insufficient to induce significant carbonate dissolution at night outgassing maintained in stream dic concentrations lower than the supersaturated dic springs source but a drop in 13 c dic indicates that ecosystem respiration had a dominant influence over outgassing although co 2 outgassing occurs it is shown to be a minor component of the dic mass balance while carbonate precipitation represents 88 of dic loss these results indicate that in stream biological processes influence carbonate mineral diagenesis in large clear water rivers

dynamics of biosonar signals in free swimming and stationary dolphins the role of source levels on the characteristics of the signals the biosonar signals of two free swimming atlantic bottlenose dolphins performing a complex sonar search for a bottom target in san diego bay were compared with the biosonar signals of a dolphin performing a target discrimination task in a net pen in the same bay a bite plate device carried by the free swimming dolphins supported a hydrophone that extended directly in front of the dolphin a biosonar measuring tool attached to the bite plate measured the outgoing biosonar signals while the dolphins conducted sonar searches each of the free swimming dolphins used different biosonar search strategy in solving the problem and the dolphins biosonar signals reflect the difference in strategy the dolphin in the pen stationed in a hoop while echolocating on a target 6 m away and reported if the indentation on a spherical target was directed toward it the signals were parameterized by determining the peak to peak source levels source energy flux density peak frequency center frequency root mean square rms bandwidth rms duration and the q of the signals some parameters were similar for the free swimming and stationary dolphins while some were significantly different suggesting biosonar signals used by free swimming animals may be different than signals used by dolphins in a pen

nearfield and farfield measurements of dolphin echolocation beam patterns no evidence of focusing the potential for bottlenose dolphins to actively focus their biosonar transmissions was examined by measuring emitted clicks in four dolphins using horizontal planar hydrophone arrays two hydrophone configurations were used a rectangular array with hydrophones 0 2 to 2 m from the dolphins and a polar array with hydrophones 0 5 to 5 m from the dolphins the biosonar task was a target change detection utilizing physical targets at ranges from 1 3 to 6 3 m with all subjects and phantom targets at simulated ranges from 2 5 to 20 m with two subjects to provide a basis for evaluating the experimental data sound fields radiated from flat and focused circular pistons were mathematically simulated using transient excitation functions similar to dolphin clicks the array measurements showed no evidence that the dolphins adaptively focused their click emissions axial amplitudes and iso amplitude contours matched the pattern of the simulation results for flat transducers and showed a single region of maximum

echolocation signals of free ranging killer whales orcinus orca and modeling of foraging for chinook salmon oncorhynchus tshawytscha fish eating resident type killer whales orcinus orca that frequent the coastal waters off northeastern vancouver island canada have a strong preference for chinook salmon oncorhynchus tshawytscha the whales in this region often forage along steep cliffs that extend into the water echolocating their prey echolocation signals of resident killer whales were measured with a four hydrophone symmetrical star array and the signals were simultaneously digitized at a sample rate of 500 khz using a lunch box pc a portable vcr recorded the images from an underwater camera located adjacent to the array center only signals emanating from close to the beam axis 1185 total were chosen for a detailed analysis killer whales project very broadband echolocation signals q equal 0 9 to 1 4 that tend to have bimodal frequency structure ninety seven percent of the signals had center frequencies between 45 and 80 khz with bandwidths between 35 and 50 khz the peak to peak source level of the echolocation signal

the hydrogen and oxygen isotopic composition of precipitation evaporated mine water and river water in montana usa summary the isotopic composition of 42 samples of rain and snow collected in 2004 were used to construct a local meteoric water line lmwl for butte montana the derived equation d 7 31 18 o 7 5 r 2 0 987 represents one of the first published lmwls based on direct precipitation for any location in the northern rocky mountains samples of underground and surface mine waters in butte including the berkeley pit lake and a nearby tailings pond define a linear trend with a much lower slope and intercept than the lmwl d 5 00 18 o 49 5 r 2 0 991 consistent with non equilibrium evaporation at an average relative humidity of roughly 65 detailed evaporation calculations are presented which indicate that the shallow berkeley pit lake was approximately 25 evaporated in october 2003 whereas the surface of the tailings pond was at least 50 evaporated the intersection of the lmwl and mine water evaporation trend was used to calculate the average composition of recharge water to the flooded mine complex d 139 18 o 18 0 these values are considerably lighter than the weighted total of precipitation for the 2004 calendar year d 118 18 o 15 3 which is partly explained by the unusually low snowfall that montana experienced in 2004 based on this study the lmwl recently proposed by kendall and coplen 2001 kendall c coplen t b 2001 distribution of oxygen 18 and deuterium in river waters across the united states hydrological processes 15 1363 1393 from regression of isotopic data from a number of montana rivers is more accurately interpreted as an evaporation line isotopic trends based on river data should be treated with caution particularly in a semi arid region such as montana where rivers are often influenced by dams and irrigation withdrawals

passive acoustic monitoring using a towed hydrophone array results in identification of a previously unknown beaked whale habitat beaked whales are diverse and species rich taxa they spend the vast majority of their time submerged regularly diving to depths of hundreds to thousands of meters typically occur in small groups and behave inconspicuously at the surface these factors make them extremely difficult to detect using standard visual survey methods however recent advancements in acoustic detection capabilities have made passive acoustic monitoring pam a viable alternative beaked whales can be discriminated from other odontocetes by the unique characteristics of their echolocation clicks in 2009 and 2010 pam methods using towed hydrophone arrays were tested these methods proved highly effective for real time detection of beaked whales in the southern california bight scb and were subsequently implemented in 2011 to successfully detect and track beaked whales during the ongoing southern california behavioral response study the three year field effort has resulted in 1 the successful classification and tracking of cuvier s ziphius cavirostris baird s berardius bairdii and unidentified mesoplodon beaked whale species and 2 the identification of areas of previously unknown beaked whale habitat use identification of habitat use areas will contribute to a better understanding of the complex relationship between beaked whale distribution occurrence and preferred habitat characteristics on a relatively small spatial scale these findings will also provide information that can be used to promote more effective management and conservation of beaked whales in the scb a heavily used naval operation and training region

mechanisms of sandstone deposition in a late proterozoic submarine canyon adelaide geosyncline south australia late proterozoic submarine canyon fills in the adelaide supergroup flinders range south australia are asymmetrical in terms of their facies coarse breccia units commonly associated with coarse grained channelized turbidite sandstone units generally occur adjacent to north walls of all the east west trending canyon incisions in contrast fine grained sandstones and mudstones within the canyon fill are generally associated with south walls in one canyon patsy springs canyon an additional element of asymmetry is associated with the prevalence of northward climbing sets of climbing ripples southward dipping stoss sides within channelized turbidites in what are interpreted to be major thalweg channels and their associated levees flute casts at the bases of indiv dual turbidite sandstones invariably indicate initial turbidity current flow to the west throughout the vertical sequences of the channel fills parallel laminations above the flute casts in each flow pass upward into climbing ripples with south dipping stoss sides implying southward lateral accretion across the channel of a levee or bar as each turbidity current decelerated the asymmetries outlined could be explained by 1 coriolis force acting on the turbidity currents or 2 the existence on a steep slope of a meandering canyon gorge confining a thalweg channel developed within subsequent canyon fill in such a situation roller coastering turbidity currents would seek outer bends of the meandering primary gorge the single accessible cross section of patsy springs canyon does not provide a unique solution however studies still in progress on a related series of canyons to the north suggest that a strongly meandering gorgelike canyon with an internal thalweg channel complex situated in an upper fan or basin slope provides the best explanation for all observations a significant coriolis force influence appears to be ruled out by observations on sandstone body geometries and associated paleocurrents the preferred model is one in which high energy turbidity currents were confined within and influenced by the steep walls of the primary canyon gorge during aggradation of canyon fill

diel patterns of algae and water quality constituents in the san joaquin river california usa abstract the san joaquin river sjr is a hypereutrophic river that contributes to hypoxia in the downstream stockton deep water ship channel oxidizable materials in the form of algal biomass from upstream sources contribute to the hypoxic conditions especially from july to october our earlier work demonstrated the existence of strong chlorophyll a diel cycles which complicated the calculation of algal loads for the watershed scale monitoring program necessary to address the total maximum daily load tmdl for dissolved oxygen do the purpose of this study was to determine if diel patterns existed for other water quality constituents and to determine the role of algal growth dynamics in driving these diel changes studies conducted between 30 june and 15 october 2004 evaluated temporal changes for several water quality constituents over four 48 h studies at two sites along the mainstem of the sjr strong diel 24 h patterns were observed for chlorophyll a and pheophytin a algal pigments temperature do ph dissolved inorganic nitrogen din nh4 n no3 n soluble reactive phosphorus srp and volatile suspended solids vss patterns of din and srp were inverse of those observed for algal pigments temperature do ph and vss the observed diel patterns of algal pigments and temperature were greater in the beginning of the summer june july and diminished by the end of summer september october due to the decreased photoperiod within a 24 h period the fluctuations observed in algal pigments and nutrients suggest that growth of algae during daylight hours and depletion at night are largely responsible for the observed diel patterns due to the observed diel variability in these water quality constituents the samples collected for tmdl programs may not be representative unless samples are collected at the daily mean for a system

preliminary evaluation of potential stable isotope and trace element productivity proxies in the oyster crassostrea gigas abstract as most bivalve mollusks are filter feeders or deposit feeders predatory septibranchs poromyacea being the notable exception they are closely linked with the activity of primary producers perhaps this is nowhere more evident than in shallow water habitats influenced by seasonal phytoplankton blooms in these systems photoautotrophs are capable of changing the physical and chemical properties of the water column in turn clams ingest large quantities of phytoplankton and precipitate their shells in these chemically altered waters thus clam shells likely archive valuable information about phytoplankton dynamics in shallow water habitats to better understand this relationship we investigated geochemical records from two potential productivity proxy systems archived in shells of the oyster crassostrea gigas that live in the san francisco bay estuary california usa here we present multi year records of shell carbon isotope 13ccarb and barium calcium ba cacarb variation these archives are compared with records of environmental variation using oxygen isotopes 18ocarb as a temporal marker we also present high resolution 13ccarb 18ocarb and ba ca profiles associated with the 2003 spring phytoplankton bloom our results suggest that the prominent positive 13ccarb excursion present in shell material deposited in the spring of 2003 most likely reflects photosynthetic enrichment of the dissolved inorganic carbon pool calibration of stable isotopes with calculated chlorophyll a concentrations measured during the bloom suggests that our 13ccarb sample variation reflects phytoplankton abundance with 3 to 4 day resolution these findings highlight the potential utility of stable isotope records as tools for reconstructing patterns of primary productivity elevated ba ca values are recorded each year in the spring thus like stable isotope profiles ba ca profiles from these specimens demarcate individual years of shell growth and establish ontogenetic age low and high resolution ba ca profiles do not however correlate with the 2003 spring phytoplankton bloom casting doubt on the relationship between ba ca ratios and phytoplankton blooms although the ba ca peak timing loosely correlates with freshwater discharge events peak amplitude does not leaving the environmental cause trigger of these peaks unknown nevertheless the san francisco bay estuary seems like an ideal environment in which to further investigate the relationship between skeletal geochemical variation and patterns of primary productivity

geochemistry water balance and stable isotopes of a clean pit lake at an abandoned tungsten mine montana usa abstract the calvert mine is a small tungsten rich scheelite skarn deposit in a remote mountainous region of southwest montana usa the open pit mine closed in the 1970s and subsequently flooded to form a pit lake that is roughly conical in shape 30 m deep and 120 m in diameter with no surface inlet or outlet the lake is holomictic with a groundwater flow through hydrology and an estimated residence time of 2 5 5 y water isotopes show that the lake is at an approximate steady state with respect to water balance and has experienced 30 evaporation the lake has a near neutral ph exceptional clarity and extremely low concentrations of nutrients sulfate and most metals including tungsten manganese concentrations are slightly elevated and increase with depth towards the sediment water interface despite seasonally anoxic conditions in the deep water dissolved fe concentrations are orders of magnitude lower than mn suggesting that insufficient organic carbon is present in the sediment of this oligotrophic lake to drive bacterial fe reduction based on stable isotope fingerprinting diffuse seepage that enters a nearby headwater stream at the base of a large waste rock pile can be directly linked to the partially evaporated pit lake however this seepage has neutral ph and low metal concentrations and poses no threats to the environment stable isotopes of dissolved inorganic carbon dic and dissolved oxygen do are used to track the relative importance of photosynthesis and respiration with depth in summer a zone of high productivity exists near the base of the chemocline releasing do that is isotopically light respiration exceeds photosynthesis below the secchi depth which causes do concentrations to approach zero towards the bottom of the lake in winter thick ice and snow cover prohibits photosynthesis however because of the low nutrient content most of the volume of the lake remains oxic through the winter overall the calvert lake is a good example of a pit lake formed from metal mining that has excellent water quality which is a result of its favorable geology paucity of sulfide minerals and hydrology flow through lake with short residence time in a temperate climate

geochemical modeling of the madison aquifer in parts of montana wyoming and south dakota stable isotope data for dissolved carbonate sulfate and sulfide are combined with water compo sition data to construct geochemical reaction models along eight flow paths in the madison aquifer in parts of wyoming montana and south dakota the sulfur isotope data are treated as an isotope dilution problem whereas the carbon isotope data are treated as rayleigh distillations all reaction models reproduce the observed chemical and carbon and sulfur isotopic composition of the final waters and are partially validated by predicting the observed carbon and sulfur isotopic compositions of dolomite and anhydrite from the madison limestone the geochemical reaction models indicate that the dominant groundwater reaction in the madison aquifer is dedolomitization calcite precipita tion and dolomite dissolution driven by anhydrite dissolution sulfate reduction ca mg2 ina cation exchange and halite dissolution are locally important particularly in central montana the groundwater system is treated as closed to c02 gas from external sources such as the soil zone or cross formational leakage but open to c02 from oxidation of organic matter coupled with sulfate reduction and other redox processes occurring within the aquifer the computed mineral mass transfers and modeled sulfur isotopic composition of madison anhydrites are mapped throughout the study area carbon 14 groundwater ages adjusted for the modeled carbon mass transfer range from modem to about 23 000 years b p and indicate flow velocities of 7 7 ftlyr 2 1 26 5 rnlyr most horizontal hydraulic conductivities calculated from darcy s law using the average 14 c flow velocities are within a factor of 5 of those based on digital simulation the calculated mineral mass transfer and adjusted 14 c groundwater ages permit determination of apparent rates of reaction in the aquifer the apparent rate of organic matter oxidation is typically 0 12 jlidol uyr sulfate and to a lesser extent ferric iron are the predominant electron acceptors the kinetic biochemical fractionation of 34 s between sulfate and hydrogen sulfide is approximately 44 o at 25 c with a temperature variation of

beaked whale and dolphin tracking using a multichannel autonomous acoustic recorder to track highly directional echolocation clicks from odontocetes passive hydrophone arrays with small apertures can be used to receive the same high frequency click on each sensor a four hydrophone small aperture array was coupled to an autonomous acoustic recorder and used for long term tracking of high frequency odontocete sounds the instrument was deployed in the spring of 2009 offshore of southern california in a known beaked whale and dolphin habitat at about 1000 m depth the array was configured as a tetrahedron with approximately 0 5 m sensor spacing time difference of arrival measurements between the six sensor pairs were used to estimate three dimensional bearings to sources both near seafloor beaked whales and near sea surface dolphins were tracked the tracks observed using this technique provide swimming and diving behavioral information for free ranging animals using a single instrument furthermore animal detection ranges were derived allowing for estimation of detection probability functions

estimated transmission beam pattern of clicks recorded from free ranging white beaked dolphins lagenorhynchus albirostris recordings were made from white beaked dolphins in icelandic waters using a four hydrophone array in a star configuration the acoustic signals were amplified and sampled to a hard disk at a rate of 800 khz per channel the 3 and 10 db beamwidths were calculated to be 8 and 10 respectively indicating a narrower transmission beam for white beaked dolphins than that reported for bottlenose dolphins tursiops truncatus the beamwidth was more similar to that found for belugas delphinapterus lucas the measured beam pattern included large side lobes perhaps due to the inclusion of off axis clicks even after applying several criteria to select only on axis clicks the directivity index was calculated to be 18 db when using all data for angles from 0 50 the calculated sound radiation from a circular piston with a radius of 6 cm driven by a white beaked dolphin click had a beam pattern very similar to the measured beam pattern for the main transmission lobe of the white beaked dolphin the directivity index was 29 db this is the first attempt to estimate the directionality index of dolphins in the field work supported by the oticon foundation and the danish national research council

an acoustic survey of beaked whales at cross seamount near hawaii an acoustic record from cross seamount southwest of hawaii revealed sounds characteristic of beaked whale echolocation at the same relative abundance year around 270 of 356 days occurring almost entirely at night the most common sound had a linear frequency upsweep from 35 to 100 khz the bandwidth of recording an interpulse interval of 0 11 s and duration of at least 932 s a less common upsweep sound with shorter interpulse interval and slower sweep rate was also present sounds matching cuvier s beaked whale were not detected and blainville s beaked whale sounds were detected on only one occasion

coupled control of land uses and aquatic biological processes on the diurnal hydrochemical variations in the five ponds at the shawan karst test site china implications for the carbonate weathering related carbon sink abstract high resolution hydrochemical data from five spring fed ponds are presented to demonstrate the effect of different land uses and aquatic biological processes on the carbon cycle at a karst analog test site the results show that hydrochemical parameters including ph and the concentrations of hco 3 ca 2 no 3 partial pressures of co 2 p co 2 and dissolved o 2 do as well as carbon isotopic compositions 13 c of hco 3 in the pond water all displayed distinct diurnal variations while those of the spring water itself were rather stable the coupled dynamic behaviors of p co 2 do and no 3 indicate a significant influence from the metabolism of submerged plants in the ponds in the afternoon when photosynthesis is the strongest the p co 2 of the five pond waters was lower even than that of the ambient atmosphere demonstrating the existence of a biological carbon pumping bcp effect similar to that in the oceans it was determined that in october autumn the bcp fluxes in the five spring fed ponds were 156 51 t c km 2 a 1 in p1 pond 1 adjoining a bare rock shore 239 83 t c km 2 a 1 in p2 adjoining uncultivated soil 414 139 t c km 2 a 1 in p3 adjoining land cultivated with corn 493 165 t c km 2 a 1 in p4 adjoining grassland and 399 124 t c km 2 a 1 of p5 adjoining brushland indicating the potentially significant role of aquatic photosynthesis in stabilizing the carbonate weathering related carbon sink in addition by comparing the dic concentrations and fluxes of dic transformed into autochthonous organic matter aoc in the five ponds the so called dic fertilization effect was found in which more aoc is produced in pond waters with higher concentrations of dic this implies that the carbon cycle driven by aquatic biological processes can be regulated by changing land use and cover the latter determining the dic concentrations further the rock weathering related carbon sink is underestimated if one only considers the dic component in surface waters instead of both dic and aoc

the fate of geothermal arsenic in the madison and missouri rivers montana and wyoming geothermal as from yellowstone national park causes high as concentrations 10 370 g l in the madison and missouri rivers in montana and wyoming arsenic transport is largely conservative in the upper basin as demonstrated by the near equivalence of dissolved and total recoverable as concentrations the constancy of as loads and consistent ratios of concentrations of as to conservative geothermal tracers diurnal cycling of as between aqueous and solid phases in response to ph induced changes in sorption equilibria causes small variations of about 10 20 in dissolved as concentrations hcl extractable as concentrations in river and lake sediment in the upper basin are variable depending on position relative to the as rich headwaters and geochemical and physical processes associated with lakes in the lower missouri river large quantities of suspended sediment from tributaries provide sufficient sorption sites for substantial conversion of as from the aqueous phase to the solid phase

echolocation signals of wild atlantic spotted dolphin stenella frontalis an array of four hydrophones arranged in a symmetrical star configuration was used to measure the echolocation signals of the atlantic spotted dolphin stenella frontalis in the bahamas the spacing between the center hydrophone and the other hydrophones was 45 7 cm a video camera was attached to the array and a video tape recorder was time synchronized with the computer used to digitize the acoustic signals the echolocation signals had bi modal frequency spectra with a low frequency peak between 40 and 50 khz and a high frequency peak between 110 and 130 khz the low frequency peak was dominant when the signal the source level was low and the high frequency peak dominated when the source level was high peak to peak source levels as high as 210 db re 1 pa were measured the source level varied in amplitude approximately as a function of the one way transmission loss for signals traveling from the animals to the array the characteristics of the signals were similar to those of captive tursiops truncatus delphinapterus leucas and pseudorca crassidens measured in open waters under controlled conditions

submarine origin for the neoproterozoic wonoka canyons south australia abstract an examination of the deeply incised ediacaran wonoka canyons in the adelaide geosyncline most recently interpreted as subaerial valleys demonstrates their submarine origin and confirms them as some of the best examples of ancient outcropping submarine canyons in the world the entire canyon fill succession is interpreted to be of deep water below wave base origin consisting of calcareous shale and siltstone together with a variety of mass flow deposits including turbidites grain flows and debris flows the canyon fill lacks definitive shallow water structures e g mud cracks fenestral fabrics or wave ripples at all stratigraphic levels canyon lining carbonate crusts that have previously been interpreted as non marine calcretes or tufas and used to suggest a non marine origin for the canyons are argued to be of deep water marine microbial origin extremely negative carbon isotope values from the canyon fill and canyon lining crusts have a primary marine origin previously interpreted deepening upward trends in the canyon fill used as evidence of a subaerial erosion episode followed by drowning are suggested to be fining upward trends caused by the transition from canyon cutting to canyon filling with the majority of the fill being of deep water slope origin the basal conglomeratic canyon fill sediments represent the last vestiges of the high energy deep water canyon erosion environment in which the incisions formed a deep water origin for the canyons is consistent with all previous stratigraphic observations of the wonoka canyons including the conspicuous lack of regional unconformities in the lower wonoka formation and their emanation from the deep water facies of the wonoka formation a submarine canyon origin also removes the need for extreme 1 km relative sea level fluctuation and associated problems i e an enclosed basin with messinian style evaporative drawdown or thermal uplift above a migrating mantle plume required by the subaerial valley hypotheses

mantle plume uplift in the sedimentary record origin of kilometre deep canyons within late neoproterozoic successions south australia in south australia canyons 200 250 km long are incised to depths of c 1 5 km in late neoproterozoic after c 590 ma marine deposits of the adelaide fold belt and canyons 90 km long and 700 m deep occur in correlative marine strata of the officer basin 1000 km to the nw in the adelaide fold belt the isotopic signature of limestone veneering canyon walls canyon sinuosity and sedimentary structures in canyon fill suggest that the canyons were cut subaerially and filled by shallow water marine deposits during coastal onlap eustacy cannot account for the kilometre scale change in sea level required for subaerial canyon erosion and chemostratigraphy and the lack of evaporites at that stratigraphic level in southern australia argue against a messinian style drawdown in each region uplift and crustal extension preceding or coeval with canyon incision are indicated by a regional unconformity turbidite or mass flow deposition and extensional faults these features and canyon incision may be explained by regional uplift above a rising mantle plume over a distance of 1000 km in southern australia flood basalt volcanism in the officer basin tentatively dated at 563 40 ma may have followed this uplift mantle plume uplift is expressed in the sedimentary record by emergent trends in facies regional thinning regional unconformities turbidites gravity slides normal faults and incised canyons and palaeovalleys

acoustic detection of biosonar activity of deep diving odontocetes at josephine seamount high seas marine protected area the temporal occurrence of deep diving cetaceans in the josephine seamount high seas marine protected area jshsmpa south west portugal was monitored using a passive acoustic recorder the recorder was deployed on 13 may 2010 at a depth of 814 m during the north atlantic treaty organization centre for maritime research and experimentation cruise sirena10 and recovered on 6 june 2010 the recorder was programmed to record 40 s of data every 2 min acoustic data analysis for the detection and classification of echolocation clicks was performed using automatic detector classification systems m3r marine mammal monitoring on navy ranges a custom matlab program and an operator supervised custom matlab program to assess the classification performance of the detector classification systems m3r cs svm algorithm contains templates to detect beaked whales sperm whales blackfish pilot and false killer whales and risso s dolphins the detections of each group of odontocetes was monitored as a function of time blackfish and risso s dolphins were detected every day while beaked whales and sperm whales were detected almost every day the hourly distribution of detections reveals that blackfish and risso s dolphins were more active at night while beaked whales and sperm whales were more active during daylight hours

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

using multipath reflections to obtain dive depths of beaked whales from a towed hydrophone array beaked whales are deep divers emitting echolocation clicks while at depth little is known about the dive behavior of most species however passive acoustic data collected with towed hydrophone arrays can provide depth information using multipath reflections of clicks coupled with a two dimensional localization of the individual data were collected during a shipboard survey in the western north atlantic ocean using a towed linear hydrophone array beaked whale tracks were classified as either cuvier s ziphius cavirostris or gervais true s mesoplodon europaeus mesoplodon mirus weighted species average depths and weighted species standard deviations were 1158 m 287 m for cuvier s n 24 and 870 m 151 m for gervais true s n 15 depth uncertainties ranged from 3 to 142 of the average depth slant ranges were corrected for depth to provide average horizontal perpendicular distance estimates the average horizontal perpendicular distance distribution exhibited fewer detections in the first bin than the second this is the first report of dive depths for gervais true s beaked whales and use of this method to obtain depths for beaked whales using a towed linear array

delphinid echolocation click detection probability on near seafloor sensors the probability of detecting echolocating delphinids on a near seafloor sensor was estimated using two monte carlo simulation methods one method estimated the probability of detecting a single click cue counting the other estimated the probability of detecting a group of delphinids group counting echolocation click beam pattern and source level assumptions strongly influenced detectability predictions by the cue counting model group detectability was also influenced by assumptions about group behaviors model results were compared to in situ recordings of encounters with risso s dolphin grampus griseus and presumed pantropical spotted dolphin stenella attenuata from a near seafloor four channel tracking sensor deployed in the gulf of mexico 25 537 n 84 632 w depth 1220 m horizontal detection range received level and estimated source level distributions from localized encounters were compared with the model predictions agreement between in situ results and model predictions suggests that