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Weekly Highlighted Publication

Early Bronze Age copper production systems in the northern Arabah Valley: New insights from archaeomagnetic study of slag deposits in Jordan and Israel

Impact:

Archaeointensity estimates are a useful tool for providing age constraints on heat-impacted archaeological materials. In this study, we retrieved archaeointensity data from ancient copper slag samples that were collected in both surveys and excavations at four EB Age copper production sites in Faynan and the northern Arabah Valley. These data, when compared to the LAC and analyzed according to their archaeological setting, provide the following insights regarding EB Age copper production in the largest ore district of the southern Levant:

  • KHI was the hub of copper processing and distribution of copper metal in the center of Faynan copper production system, channeling raw copper from smelting sites in its vicinity for further refining and casting of ingots and tools. The first small scale activity took place during the later part of the EB II, contemporaneous to the copper processing site of Barqa el-Hetiye. However, the main phase of activity was during the late EB III – early EB IV, with probable limited activity also in the late EB IV.
  • The main phase of copper production in EB Age Faynan strongly coincides with the rise and fall of the Egyptian Old Kingdom. This connection is best manifested in the settlement wave of the Negev Highlands, which predominantly reflects transport of copper in an east-west direction. This phase is the first large scale copper production in the region.
  • Copper metallurgy at the site of Ashalim is probably dated to the late EB II. The site, located on the main road between Faynan and Arad, is probably related to copper trade between Faynan and the fertile region of the southern Levant. This unique site includes, in addition to the metallurgical remains, dozens of standing stones, evidence of cultic activity that might be related to copper smelting and/or trade.
  • In addition, our study provides new data from two different sites (KHI and Giv’at Hazeva) that support the unique Iron Age archaeointensity ‘spikes’ (Ben-Yosef et al., 2009 and Shaar et al., 2011). The archaeointensity values from Giv’at Hazeva are the highest recorded to date (exceeding 300 ZAm2), and add to our understanding of the geomagnetic field, one of the more enigmatic phenomena of the Earth.

Search Recent Publications

  • Highlighted Publication
    Abstract Summary:

    Although marine bacteria were identified nearly two decades ago as potential sources for strong iron-binding organic ligands detected in seawater, specific linkages between ligands detected in natural water and the microbial community remain unclear. We compared the production of different classes of iron-binding ligands, dissolved iron and macronutrient concentrations, and phytoplankton and bacterioplankton assemblages in a series of iron...

  • Highlighted Publication Spatial maps of linear trends in potential intensity
    Abstract Summary:

    Intensity changes in landfalling typhoons are of great concern to East and Southeast Asian countries(1). Regional changes in typhoon intensity, however, are poorly known owing to inconsistencies among different data sets(2-8). Here, we apply cluster analysis to bias-corrected data and show that, over the past 37 years, typhoons that strike East and Southeast Asia have intensified by 12-15%, with the proportion of storms of categories 4 and 5...

  • Highlighted Publication
    Abstract Summary:

    Aftershocks are often triggered by static- and/or dynamic-stress changes caused by mainshocks. The relative importance of the two triggering mechanisms is controversial at near-to-intermediate distances. We detected and located 48 previously unidentified large early aftershocks triggered by earthquakes with magnitudes between >= 7 and 8 within a few fault lengths (approximately 300 kilometers), during times that high-amplitude surface...

  • Highlighted Publication
    Abstract Summary:

    The excretion of nitrogenous waste products in the form of ammonia (NH3) and ammonium (NH4 (+)) is a fundamental process in aquatic organisms. For mytilid bivalves, little is known about the mechanisms and sites of excretion. This study investigated the localization and the mechanisms of ammonia excretion in mytilid mussels. An Rh protein was found to be abundantly expressed in the apical cell membrane of the plicate organ, which was...

  • Highlighted Publication Architectural features at the Ashalim Site.
    Abstract Summary:

    This paper presents results of an archaeomagnetic study of slag from four Early Bronze (EB) Age copper production sites in the Faynan Copper Ore District and the northern Arabah Valley (modern Israel and Jordan). The results provide age constraints for metallurgical activities at these sites. Together with previously published data, they indicate copper production around ca. 2900 cal. BCE (EB II-III transition) and between ca. 2600-1950 cal....

  • Highlighted Publication Time series plots of trophy fish weight.
    Abstract Summary:

    In California, recreational fisheries contribute a significant amount to coastal economies, with pelagic and coastal pelagic species constituting a principal set of target species during summer and fall. Although traditional catch frequency (landings) data sets exist for these species, size-specific information is limited, especially for the largest size-classes. We digitized weekly records of trophy catch reported in the "Whoppers of the...

  • Highlighted Publication Transmembrane adenylyl cyclases (tmACs) in vacuolar-type H+-ATPase (VHA)-rich cells.
    Roa J.N, Tresguerres M.  2016.  Soluble adenylyl cyclase is an acid-base sensor in epithelial base-secreting cells. Am J Physiol Cell PhysiolAm J Physiol Cell Physiol. 311:C340-9.
    Abstract Summary:

    Blood acid-base regulation by specialized epithelia, such as gills and kidney, requires the ability to sense blood acid-base status. Here, we developed primary cultures of ray (Urolophus halleri) gill cells to study mechanisms for acid-base sensing without the interference of whole animal hormonal regulation. Ray gills have abundant base-secreting cells, identified by their noticeable expression of vacuolar-type H(+)-ATPase (VHA), and also...

  • Highlighted Publication
    Guass O., Haapanen L.M, Dowd S.E, Sirovic A., McLaughlin R.W.  2016.  Analysis of the microbial diversity in faecal material of the endangered blue whale, Balaenoptera musculus. Antonie Van Leeuwenhoek International Journal of General and Molecular Microbiology. 109:1063-1069.
    Abstract Summary:

    Using bacterial and fungal tag-encoded FLX-Titanium amplicon pyrosequencing, the microbiota of the faecal material of two blue whales living in the wild off the coast of California was investigated. In both samples the most predominant bacterial phylum was the Firmicutes with Clostridium spp. being the most dominant bacteria. The most predominant fungi were members of the phylum Ascomycota with Metschnikowia spp. being the most dominant. In...

  • Highlighted Publication Difference in climate response pattern between aerosol- and GHG-forcing runs
    Abstract Summary:

    Spatial patterns of climate response to changes in anthropogenic aerosols and well-mixed greenhouse gases ( GHGs) are investigated using climate model simulations for the twentieth century. The climate response shows both similarities and differences in spatial pattern between aerosol and GHG runs. Common climate response between aerosol and GHG runs tends to be symmetric about the equator. This work focuses on the distinctive patterns that...

  • Highlighted Publication Clouds over eastern United States
    Abstract Summary:

    Clouds substantially affect Earth’s energy budget by reflecting solar radiation back to space and by restricting emission of thermal radiation to space. They are perhaps the largest uncertainty in our understanding of climate change, owing to disagreement among climate models and observational datasets over what cloud changes have occurred during recent decades and will occur in response to global warming. This is because observational...

  • Highlighted Publication Global TC's locations color coded with Saffir–Simpson Scale from JTWC (1979–2013) and NHC (1979–2013).
    Abstract Summary:

    Global data from drifters of the Surface Velocity Program (Niiler, 2001) and tropical cyclones (TCs) from the Joint Typhoon Warning Center and National Hurricane Center were analyzed to demonstrate strong ocean currents and their characteristics under various storm intensities in the Northern Hemisphere (NH) and in the Southern Hemisphere (SH). Mean TC's translation speed (U-h) is faster in the NH (similar to 4.7 m s(-1)) than in the SH (...

  • Highlighted Publication Regional bathymetry of the CNTL15RR cruise
    DeSanto J.B, Sandwell DT, Chadwell C.D.  2016.  Seafloor geodesy from repeated sidescan sonar surveys. Journal of Geophysical Research-Solid Earth. 121:4800-4813.
    Abstract Summary:

    Accurate seafloor geodetic methods are critical to the study of marine natural hazards such as megathrust earthquakes, landslides, and volcanoes. We propose digital image correlation of repeated shipboard sidescan sonar surveys as a measurement of seafloor deformation. We test this method using multibeam surveys collected in two locales: 2500m deep lightly sedimented seafloor on the flank of a spreading ridge and 4300m deep heavily sedimented...

  • Highlighted Publication
    Abstract Summary:

    The structure and variability of upper-ocean properties in the Bay of Bengal (BoB) modulate air-sea interactions, which profoundly influence the pattern and intensity of monsoonal precipitation across the Indian subcontinent. In turn, the bay receives a massive amount of freshwater through river input at its boundaries and from heavy local rainfall, leading to a salinity-stratified surface ocean and shallow mixed layers. Small-scale...

  • Highlighted Publication
    Abstract Summary:

    A large patch of anomalously warm water (nicknamed "the Blob") appeared off the coast of Alaska in the winter of 2013-2014 and subsequently stretched south to Baja California. This northeastern Pacific warm-water anomaly persisted through the end of 2015. Scientists and the public alike noted widespread changes in the biological structure and composition of both open ocean and coastal ecosystems. Changes included geographical shifts of...

  • Highlighted Publication Blastopore view of sea urchin early gastrulae
    Abstract Summary:

    The multidrug resistance protein (MRP) family encodes a diverse repertoire of ATP-binding cassette (ABC) transporters with multiple roles in development, disease, and homeostasis. Understanding MRP evolution is central to unraveling their roles in these diverse processes. Sea urchins occupy an important phylogenetic position for understanding the evolution of vertebrate proteins and have been an important invertebrate model system for study...

  • Highlighted Publication Map of the world showing swirls of aerosols
    Allen RJ, Ajoku O..  2016.  Future aerosol reductions and widening of the northern tropical belt. Journal of Geophysical Research-Atmospheres. 121:6765-6786.
    Abstract Summary:

    Observations show that the tropical belt has widened over the past few decades, a phenomenon associated with poleward migration of subtropical dry zones and large-scale atmospheric circulation. Although part of this signal is related to natural climate variability, studies have identified an externally forced contribution primarily associated with greenhouse gases (GHGs) and stratospheric ozone loss. Here we show that the increase in aerosols...

  • Highlighted Publication Image courtesy of Alessandra de Martino and Chris Bowler, Stazione Zoologica and Ecole Normale Supérieure.
    Abstract Summary:

    Diatoms are a dominant group of eukaryotic phytoplankton that contribute substantially to global primary production and the cycling of important elements such as carbon and nitrogen. Heterotrophic bacteria, including members of the gammaproteobacteria, are commonly associated with diatom populations and may rely on them for organic carbon while potentially competing with them for other essential nutrients. Considering that bacterioplankton...

  • Highlighted Publication Relief map showing location of Mariana Trench sampling sites
    Abstract Summary:

    Relatively few studies have described the microbial populations present in ultra-deep hadal environments, largely as a result of difficulties associated with sampling. Here we report Illumina-tag V6 16S rRNA sequence-based analyses of the free-living and particle-associated microbial communities recovered from locations within two of the deepest hadal sites on Earth, the Challenger Deep (10,918 meters below surface-mbs) and the Sirena Deep (...

  • Highlighted Publication Map view of the detected swarm (solid circle) events in the San Jacinto Fault Zone.
    Abstract Summary:

    Understanding earthquake clustering in space and time is important but also challenging because of complexities in earthquake patterns and the large and diverse nature of earthquake catalogues. Swarms are of particular interest because they likely result from physical changes in the crust, such as slow slip or fluid flow. Both swarms and clusters resulting from aftershock sequences can span a wide range of spatial and temporal scales. Here we...

  • Highlighted Publication A pelagic polychaete annelid called Alciope. Photo by Greg Rouse.
    Sperling EA, Frieder CA, Levin LA.  2016.  Biodiversity response to natural gradients of multiple stressors on continental margins. Proceedings of the Royal Society of London B: Biological Sciences. 283
    Abstract Summary:

    Sharp increases in atmospheric CO2 are resulting in ocean warming, acidification and deoxygenation that threaten marine organisms on continental margins and their ecological functions and resulting ecosystem services. The relative influence of these stressors on biodiversity remains unclear, as well as the threshold levels for change and when secondary stressors become important. One strategy to interpret adaptation potential and predict...

  • Highlighted Publication Atlantic warming generates anomalous atmospheric deep convection, mimicking the Gill convective model
    Abstract Summary:

    During the past three decades, tropical sea surface temperature (SST) has shown dipole-like trends, with warming over the tropical Atlantic and Indo-western Pacific but cooling over the eastern Pacific. Competing hypotheses relate this cooling, identified as a driver of the global warming hiatus(1,2), to the warming trends in either the Atlantic(3,4) or Indian Ocean(5). However, the mechanisms, the relative importance and the interactions...

  • Highlighted Publication Cruise overview. Upper left panel shows CRD study region in the Eastern Tropical Pacific.
    Abstract Summary:

    The Costa Rica Dome is a picophytoplankton-dominated, open-ocean upwelling system in the Eastern Tropical Pacific that overlies the ocean's largest oxygen minimum zone. To investigate the efficiency of the biological pump in this unique area, we used shallow (90-150 m) drifting sediment traps and Th-234: U-238 deficiency measurements to determine export fluxes of carbon, nitrogen and phosphorus in sinking particles. Simultaneous measurements...

  • Highlighted Publication   Map of WIS/MIS subglacial lakes, GPS instrumentation, and record of lake activity.
    Abstract Summary:

    Height change anomalies in satellite altimeter data have been interpreted as the surface expressions of basal water moving into and out of subglacial lakes. These signals have been mapped throughout Antarctica on timescales of months to years, but only broad connections have been made between active lakes and ice dynamics. We present the first high-frequency observations of ice velocity evolution due to a cascading subglacial lake drainage...

  • Highlighted Publication Conceptual diagram displaying the proposed relationship
    Abstract Summary:

    Large, migratory predators are often cited as sentinel species for ecosystem processes and climate-related changes, but their utility as indicators is dependent upon an understanding of their response to environmental variability. Documentation of the links between climate variability, ecosystem change and predator dynamics is absent for most top predators. Identifying species that may be useful indicators and elucidating these mechanistic...

  • Highlighted Publication Tel Megiddo by Itamar Grinberg https://www.flickr.com/photos/visitisrael/7723472130
    Abstract Summary:

    Geomagnetic field measurements from the past few centuries show heightened secular variation activity in the southern hemisphere associated with the south Atlantic anomaly (SAA). It is uncertain whether geomagnetic anomalies at a similar scale have existed in the past owing to limited coverage and uncertainties in the paleomagnetic database. Here we provide new evidence from archaeological sources in the Levant suggesting a large positive...

  • Highlighted Publication The spatial structure of the second EOF of 10-m winds over North Africa.
    Abstract Summary:

    African dust emission and transport exhibits variability on diurnal(1) to decadal(2) timescales and is known to influence processes such as Amazon productivity(3), Atlantic climate modes(4), regional atmospheric composition and radiative balance(5) and precipitation in the Sahel(6). To elucidate the role of African dust in the climate system, it is necessary to understand the factors governing its emission and transport. However, African dust...

  • Highlighted Publication On January 6, 2002, Santa Ana winds blew dust from interior deserts and other dry areas.
    Abstract Summary:

    Santa Ana Winds (SAWs) are an integral feature of the regional climate of Southern California/Northern Baja California region, but their climate-scale behavior is poorly understood. In the present work, we identify SAWs in mesoscale dynamical downscaling of a global reanalysis from 1948 to 2012. Model winds are validated with anemometer observations. SAWs exhibit an organized pattern with strongest easterly winds on westward facing downwind...

  • Highlighted Publication
    Abstract Summary:

    Measurements of energy dissipated in breaking laboratory waves, averaged over time and space and directly visualized with a bioluminescent technique, are presented. These data show that the energy dissipated in the crest of the breaking waves is constrained: average turbulence intensity within the crest saturates at around 0.5-1.2 W kg(-1), whereas breaking crest volume scales with wave energy lost. These results are consistent with...

  • Highlighted Publication Profiles across the Imperial Fault showing InSAR-derived fault-parallel velocity from track 77+306
    Abstract Summary:

    We analyze a suite of geodetic observations across the Imperial Fault in southern California that span all parts of the earthquake cycle. Coseismic and postseismic surface slips due to the 1979 M 6.6 Imperial Valley earthquake were recorded with trilateration and alignment surveys by Harsh (1982) and Crook et al. (1982), and interseismic deformation is measured using a combination of multiple interferometric synthetic aperture radar (InSAR)-...

  • Highlighted Publication Tsunami warning maps and coastline amplitude predictions.
    Abstract Summary:

    We demonstrate a flexible strategy for local tsunami warning that relies on regional geodetic and seismic stations. Through retrospective analysis of four recent tsunamigenic events in Japan and Chile, we show that rapid earthquake source information, provided by methodologies developed for earthquake early warning, can be used to generate timely estimates of maximum expected tsunami amplitude with enough accuracy for tsunami warning. We...

  • Highlighted Publication Photo courtesy Energy.gov
    Abstract Summary:

    Geothermal energy is an important source of renewable energy, yet its production is known to induce seismicity. Here we analyze seismicity at the three largest geothermal fields in California: The Geysers, Salton Sea, and Coso. We focus on resolving the temporal evolution of seismicity rates, which provides important observational constraints on how geothermal fields respond to natural and anthropogenic loading. We develop an iterative,...

  • Highlighted Publication Anomalies of surface temperature and sea-level pressure
    Abstract Summary:

    The Earth's energy budget for the past four decades can now be closed(1), and it supports anthropogenic greenhouse forcing as the cause for climate warming. However, closure depends on invoking an unrealistically large increase in aerosol cooling(2) during the so-called global warming hiatus since the late 1990s (refs 3,4) that was due partly to tropical Pacific Ocean cooling(5-7). The difficulty with this closure lies in the assumption that...

  • Highlighted Publication The prototype High Seas Telemetered Seismographic Observatory.
    Abstract Summary:

    We describe a new technology that can provide near real-time telemetry of sensor data from the ocean bottom without a moored buoy or a cable to shore. The breakthrough technology that makes this system possible is an autonomous surface vehicle called a Wave Glider developed by Liquid Robotics, Inc. of Sunnyvale, CA., which harvests wave and solar energy for motive and electrical power. We present results from several deployments of a...

  • Highlighted Publication A look at the collection system;  Phylogenetic tree of 16S rRNA gene sequence.
    Abstract Summary:

    Hadal ecosystems are found at a depth of 6,000 m below sea level and below, occupying less than 1% of the total area of the ocean. The microbial communities and metabolic potential in these ecosystems are largely uncharacterized. Here, we present four single amplified genomes (SAGs) obtained from 8,219 m below the sea surface within the hadal ecosystem of the Puerto Rico Trench (PRT). These SAGs are derived from members of deep-sea clades,...

  • Highlighted Publication Maps of signal groups corresponding to three events
    Abstract Summary:

    We have developed a novel method to detect and locate geophysical events that makes use of any sufficiently dense sensor network. This method is demonstrated using acoustic sensor data collected in 2013 at the USArray Transportable Array (TA). The algorithm applies Delaunay triangulation to divide the sensor network into a mesh of three-element arrays, called triads. Because infrasound waveforms are incoherent between the sensors within each...

  • Highlighted Publication Flooding across Highway 78 in San Diego County, California, 22 Jul 2013. [Photo credit: NOAA]
    Abstract Summary:

    During the North American Monsoon, low-to-midlevel moisture is transported in surges from the Gulf of California and Eastern Pacific Ocean into Mexico and the American Southwest. As rising levels of precipitable water interact with the mountainous terrain, severe thunderstorms can develop, resulting in flash floods that threaten life and property. The rapid evolution of these storms, coupled with the relative lack of upper-air and surface...

  • Highlighted Publication Representative micrographs showing accumulation of fluorone-based and bodipy-conjugated chemicals
    Abstract Summary:

    ATP-binding cassette (ABC) transporters are evolutionarily conserved proteins that pump diverse substrates across membranes. Many are known to efflux signaling molecules and are extensively expressed during development. However, the role of transporters in moving extracellular signals that regulate embryogenesis is largely unexplored. Here, we show that a mesodermal ABCC (MRP) transporter is necessary for endodermal gut morphogenesis in sea...

  • Highlighted Publication
    Abstract Summary:

    Antarctic penguins survive some of the harshest conditions on the planet. Emperor penguins breed on the sea ice where temperatures drop below -40 degrees C and forage in -1.8 degrees C waters. Their ability to maintain 38 degrees C body temperature in these conditions is due in large part to their feathered coat. Penguins have been reported to have the highest contour feather density of any bird, and both filoplumes and plumules (downy...

  • Highlighted Publication A distinct shift in echolocation behavior from day to night.
    Abstract Summary:

    Many terrestrial and marine species have a diel activity pattern, and their acoustic signaling follows their current behavioral state. Whistles and echolocation clicks on long-term recordings produced by melon-headed whales (Peponocephala electra) at Palmyra Atoll indicated that these signals were used selectively during different phases of the day, strengthening the idea of nighttime foraging and daytime resting with afternoon socializing...

  • Highlighted Publication Intraseasonal altimetric SSH (cm) from delayed-time AVISO product
    Abstract Summary:

    Using more than 10 years of Argo temperature and salinity profiles (2004-14), a new optimal interpolation (OI) of the upper ocean in the equatorial Pacific is presented. Following Roemmich and Gilson's procedures, which were formulated for describing monthly large-scale anomalies, here every 5 days anomaly fields are constructed with improvements in the OI spatial covariance function and by including the time domain. The comparison of Argo...

  • Highlighted Publication Mean settlement of (A)  Orbicella faveolata and (B)  Agaricia humilis larvae
    Abstract Summary:

    Oil spills cause damage to marine wildlife that lasts well past their immediate aftermath. Marine offspring that must settle and metamorphose to reach adulthood may be particularly prone to harm if the legacy of oil exposure interrupts later transitions across life stages. Following an oil spill on Curacao, we found that oil-contaminated seawater reduced settlement of 2 coral species by 85% and 40% after exposure had ended. The effect of...

  • Highlighted Publication Cumulative slip distribution of and static stress drop due to the Gorkha earthquake.
    Abstract Summary:

    Detailed geodetic imaging of earthquake ruptures enhances our understanding of earthquake physics and associated ground shaking. The 25 April 2015 moment magnitude 7.8 earthquake in Gorkha, Nepal was the first large continental megathrust rupture to have occurred beneath a high-rate (5-hertz) Global Positioning System (GPS) network. We used GPS and interferometric synthetic aperture radar data to model the earthquake rupture as a slip pulse...

  • Highlighted Publication Snapshots of evolving volcanic plume from Santiaguito volcano
    Abstract Summary:

    The details of volcanic plume source conditions or internal structure cannot readily be revealed by simple visual images or other existing remote imaging techniques. For example, one predominant observable quantity, the spreading rate in steady or quasi-steady volcanic plumes, is independent of source buoyancy flux. However, observable morphological features of short-duration unsteady plumes appear to be strongly controlled by volcanic source...

  • Highlighted Publication Time-integrated images of backprojected P waves.
    Abstract Summary:

    We analyze the rupture process of the 25 April 2015 Nepal earthquake with globally recorded teleseismic P waves. The rupture propagated east-southeast from the hypocenter for about 160km with a duration of similar to 55s. Backprojection of both high-frequency (HF, 0.2 to 3Hz) and low-frequency (LF, 0.05 to 0.2Hz) P waves suggest a multistage rupture process. From the low-frequency images, we resolve an initial slow downdip (northward) rupture...

  • Highlighted Publication Schematic viewof dielcycle of dissipation
    Abstract Summary:

    Sverdrup (1953. On conditions for the vernal blooming of phytoplankton. Journal du Conseil International pour l'Exploration de la Mer, 18: 287295) was quite careful in formulating his critical depth hypothesis, specifying a "thoroughly mixed top layer" with mixing "strong enough to distribute the plankton organisms evenly through the layer". With a few notable exceptions, most subsequent tests of the critical depth hypothesis have ignored...

  • Highlighted Publication NOAA's National Weather Service (NWS) Collection, Allen Shimada, NOAA/NMFS/OST/AMD
    Xu Y, Xie SP.  2015.  Ocean mediation of tropospheric response to reflecting and absorbing aerosols. Atmospheric Chemistry and Physics. 15:5827-5833.
    Abstract Summary:

    Radiative forcing by reflecting (e.g., sulfate, SO4) and absorbing (e.g., black carbon, BC) aerosols is distinct: the former cools the planet by reducing solar radiation at the top of the atmosphere and the surface, without largely affecting the atmospheric column, while the latter heats the atmosphere directly. Despite the fundamental difference in forcing, here we show that the structure of the tropospheric response is remarkably similar...

  • Highlighted Publication Unit source locations generating the largest amplitude waves at target sites on the U.S. West Coast.
    Abstract Summary:

    Tsunami propagation simulations are used to identify which tsunami source locations would produce the highest amplitude waves on approach to key population centers along the U.S. West Coast. The reasons for preferential influence of certain remote excitation sites are explored by examining model time sequences of tsunami wave patterns emanating from the source. Distant bathymetric features in the West and Central Pacific can redirect tsunami...

  • Highlighted Publication Near-field processes in the Luzon Strait
    Abstract Summary:

    Internal gravity waves, the subsurface analogue of the familiar surface gravity waves that break on beaches, are ubiquitous in the ocean. Because of their strong vertical and horizontal currents, and the turbulent mixing caused by their breaking, they affect a panoply of ocean processes, such as the supply of nutrients for photosynthesis(1), sediment and pollutant transport(2) and acoustic transmission(3); they also pose hazards for man-made...

  • Highlighted Publication Ecological health index.
    Abstract Summary:

    The recovery of historic community assemblages on reefs is a primary objective for the management of marine ecosystems. Working under the overall hypothesis that, as fishing pressure increases, the abundance in upper trophic levels decreases followed by intermediate levels, we develop an index that characterizes the comparative health of rocky reefs. Using underwater visual transects to sample rocky reefs in the Gulf of California, Mexico, we...

  • Highlighted Publication Schematic of the global model of climate and sea ice described in section 2.
    Wagner T.JW, Eisenman I.  2015.  How climate model complexity influences sea ice stability. Journal of Climate. 28:3998-4014.
    Abstract Summary:

    Record lows in Arctic sea ice extent have been making frequent headlines in recent years. The change in albedo when sea ice is replaced by open water introduces a nonlinearity that has sparked an ongoing debate about the stability of the Arctic sea ice cover and the possibility of Arctic "tipping points.'' Previous studies identified instabilities for a shrinking ice cover in two types of idealized climate models: (i) annual-mean...