Kodiak Island Research Articles

Nematode Parasites of Rockfish (Sebastes spp.) and Cod (Gadus spp.) from Waters near Kodiak Island Alaska, USA

Distribution and abundance of common parasitic nematodes in marine fishes is not well documented in many geographic regions. Understanding the influence of large-scale environmental changes on infection rates of fish by nematodes requires quantitative assessments of parasite abundance for multiple host species. We collected samples of two species of cod and eight species of rockfish (total of 232 specimens) from waters near Kodiak Island, Alaska, USA during Spring and Summer of 2015, and dissected and recorded all internal nematode parasites. We quantified the prevalence and intensity of nematode parasites in the ten host species, and tested for differences in prevalence among host species. We found three species of nematode: Anisakis simplex, sensu lato (Van Thiel), Pseudoterranova decipiens, sensu lato (Krabbe), and Hysterothylacium sp. (Ward and Magath). Eighty-two percent of the examined fish were infected with at least one parasitic nematode. The overall prevalence of P. decipiens, A. simplex, and Hysterothylacium sp. was 56%, 62%, and 2%, respectively. Anisakis simplex and P. decipiens were abundant and present in all ten species of host fish examined, whereas Hysterothylacium sp. was rare and found in only five of the host fish species. Prevalence and mean intensity of P. decipiens and A. simplex varied across the ten host species, and the number of parasites varied substantially among individual hosts within host species. The mean intensity of P. terranova and A. simplex in our study was substantially higher than the mean intensity for these same species from multiple other locations in a recent meta-analysis. This study provides a baseline of nematode parasite abundance in long-lived fish in waters near Kodiak Island, AK, and fills an important gap in our quantitative understanding of patterns of occurrence and abundance of these common and widespread parasites of marine fish.

The contribution of diet to the dramatic reduction of the 2013 year class of Gulf of Alaska walleye pollock (Gadus chalcogrammus)

AbstractA survey‐based time series (2001–2019) showed that age‐0 walleye pollock (Gadus chalcogrammus) occurred in very high abundances in 2013 compared with other years; however, recruitment of the 2013 year class to age‐1 was lower than average. Diet composition of age‐0 fish was examined from the 2013 year class to assess the potential impact of the consumed prey on walleye pollock. High abundances of smaller age‐0 fish were found at stations southwest of the Shumagin Islands compared with low abundances of larger fish found surrounding Kodiak Island. Fish in the southwest region showed a higher intake of low‐quality food items such as pteropods and larvaceans compared with fish in the northwest region that had consumed mostly higher quality prey such as large copepods and euphausiids. Even though no significant differences were found in fish condition between regions overall, spatial differences in fish weight were found after accounting for sample day of year. Prey‐specific Index of Relative Importance analysis showed southwest region fish had consumed a larger diversity of taxa, whereas fish from the rest of study area primarily consumed large copepods and euphausiids. These results suggest that high abundances of smaller pollock found in the southwestern part of the study region consumed a higher percentage of low‐quality, lipid‐poor prey taxa, which likely contributed to reduced overwinter survival and increased mortality.

Platinum and gold placer from Tugidak Island, Alaska: Platinum-group minerals and their inclusions, gold, and chromite mineralogy

ABSTRACT Black sand beach placers from Kodiak, Sitkinak, and Tugidak Islands, Alaska, have been mined intermittently for gold and minor platinum-group alloys for more than 100 years. High-grade platinum-rich magnetic separate and accompanying black sand from the southern beach placer of Tugidak Island were studied using electron microprobe WDS and scanning electron microscope EDS; mineral classification and identification were based on these techniques. The major platinum mineral is isoferroplatinum, followed by minor tetraferroplatinum and tulameenite, and rare ferronickelplatinum. Two types of alteration were identified in about 3–4% of the alloy grains: rim formation involving Pt loss and increased Fe, Ni, and/or Cu, and fracturing and vein filling by Cu-rich alloy. Ruthenium-Ir-Os-Pt alloys occur as inclusions and veins as well as form part of composite grains. Ten percent of the alloy grains contain a large variety of platinum-group minerals (PGM). Inclusions of cuprorhodsite, malanite, cuproiridsite, laurite, erlichmanite, cooperite, braggite, bowieite, kashinite, miassite, hollingworthite, irarsite, sperrylite, stillwaterite, genkinite, stibiopalladinite, keithconnite, zvyagintsevite, and probable palladodymite and vincentite were identified. Two unidentified inclusion phases also occur. Most of the PGM inclusions are primary and were trapped by a growing crystal from a melt; some inclusions exhibit textures that suggest trapping of an As,Te,S-rich immiscible melt. Secondary inclusions and evidence of deformation were observed in a few alloy grains. Associated with PGM inclusions or as separate inclusions are various base-metal sulfides. Two silicate-melt inclusions in one isoferroplatinum grain have an andesite–shoshonite composition. Minor gold and Ag-rich gold in the high-grade magnetic separate contain magnetite, pyrrhotite, and chromite inclusions. The gold composition suggests that their sources are the numerous quartz veins and apophyses related to granitoids on Kodiak Island. The composition of the placer chromite is similar to chromite from the Border Ranges mélange fault system and suggests that the Uyak Complex ultramafic and mafic rocks are part of a supra-subduction-zone ophiolite and are the source of the platinum-group minerals.

Nuna Nalluyuituq (The Land Remembers): Remembering landscapes and refining methodologies through community‐based remote sensing in the Yukon‐Kuskokwim Delta, Southwest Alaska

AbstractThe following article outlines a collaborative, multidisciplinary approach to remote sensing in Southwest Alaska's Yukon‐Kuskokwim (Y‐K) Delta that combines ethnographic inquiry and remote sensing to monitor, detect and preserve cultural resources for Alaskan Native communities. Because distinctive vegetation differences are readily visible on cultural sites during the summer months, the analysis of multispectral imagery obtained from remote sensing is particularly useful. In turn, we demonstrate the efficacy of this protocol on pre‐contact settlement sites along the Ayakulik River system on Kodiak Island using a normalized difference vegetation index (NDVI) raster of the study area. Here, support vector machine (SVM) supervised classification was highly effective at identifying spectral patterns associated with anthropogenic activity while ethnographic data helped rule out false‐positive cases. In addition, we provide the results of a 2019 archaeological prospection survey carried out in conjunction with the ongoing Nunalleq Project in Quinhagak, Alaska, to further highlight the value of ethnographic data collection, ethnobotanical surveys and unmanned aerial vehicle (UAV)‐based spectroscopy alongside SVM supervised classification. Finally, we propose three suggestions for future research on Yup'ik landscapes in the Y‐K Delta regarding citizen science, language preservation and the use of collaborative online maps for community‐based decision making.

Spatial and temporal variability of dissolved aluminum and manganese in surface waters of the northern Gulf of Alaska

The Northern Gulf of Alaska (NGA) shelf is a productive high-latitude environment where nutrient dynamics are greatly impacted by the seasonal variability in freshwater input. Iron is a key nutrient on the NGA shelf that directly modulates primary production, and freshwater is a major input of iron to the NGA shelf. However, variability in the input of dissolved iron from freshwater sources is obscured by high biological uptake and by the concentration of organic ligands, which bind iron and help maintain it in solution. Riverine inputs of other lithogenic elements such as aluminum and manganese are expected to behave quasi-conservatively on the NGA shelf and could help provide insight into the variability of iron input in this region.Here we present the seasonal (spring, summer, and fall) distribution of dissolved aluminum (dAl) and manganese (dMn) observed during 2018 and 2019 in the NGA region. Data were obtained during the NGA Long Term Ecological Research (LTER) site cruises and include several surface transects from Kayak Island to Kodiak Island, vertical profiles at several locations sparsely distributed throughout the shelf, and surface information from a Copper River plume study. We find that seasonal patterns in the surface concentrations of dMn and dAl mirrored annual glacial melt cycles, with the lowest values observed in spring and higher values in summer and fall. Sharp cross-shelf gradients were observed for both metals particularly in summer and fall. Surface concentrations decreased (by 1–2 orders of magnitude) away from the outflow of the Copper River, the major point source of freshwater within the NGA LTER site. Extremely high concentrations in the Copper River plume (≤1395 nM dAl, ≤128 nM dMn) and strong correlations with salinity (p = 7.9E-14 for dAl, 1.4E-14 for dMn) highlight the quasi-conservative nature of these metals within the plume. Enhanced dAl and dMn concentrations within nepheloid layers in subsurface waters indicate regions where a sedimentary source of iron could also be important. Residence times for dAl and dMn in surface waters over the NGA shelf were estimated to be 31 days (dAl) and 42 days (dMn) on average based on summer and fall data from both years.

Covariability of Fraser River sockeye salmon productivity and phytoplankton biomass in the Gulf of Alaska

AbstractUsing satellite ocean color measurements and sockeye salmon stock–recruit data from 1995 to 2016, our analysis reveals a significant, positive relationship between Fraser River sockeye productivity and summer chlorophyll a concentrations (Chl‐a) in the northwestern Gulf of Alaska. The correlation is the strongest for the area adjacent to the continental shelf near Kodiak Island (northern Gulf of Alaska), during midsummer of the juvenile sockeye salmon ocean entry year. The inclusion of (Chl‐a) data from this region significantly improved the performance of Ricker stock–recruitment models for ten out of eighteen Fraser River stocks. We discuss the potential oceanographic processes driving the correlation between (Chl‐a) and sockeye productivity. During midsummer, positive sea‐level anomalies in the offshore waters near Kodiak Island suggest the presence of mesoscale eddies, which can transport nutrients to this region and concentrate phytoplankton and zooplankton biomass, thus supporting enhanced sockeye salmon prey abundance. These results suggest a mechanism linking mesoscale oceanographic dynamics to sockeye salmon productivity, and identify a potentially important region for future studies of Fraser River sockeye salmon survival.

An Optical Assessment of Weathervane Scallop Density and Abundance Off Kodiak Island, Alaska

Since 2000, information to support the sustainable management of the weathervane scallop Patinopecten caurinus in the Gulf of Alaska is largely derived from fishery-dependent observations from a small fleet (≤8 vessels total). As a supplement to this information, the Alaska Department of Fish and Game collected more than one million high-resolution underwater photographs of the sea floor in five previously unsurveyed scallop beds off Kodiak Island during the spring of 2014. Weathervane scallop distribution, abundance, and size composition in these beds were assessed by analyzing more than 150,000 images subsampled in 50-image strips (stations) using a 100-m grid. In addition, the influence of local abiotic habitat features, including depth, substrate, and shell remains, on weathervane scallop distributions was explored. An estimated 26.8 [95% confidence interval (CI) = 23.5–30.7] million scallops in the five beds, with densities ranging from 0.08 (95% CI = 0.067–0.084) to 0.26 (95% CI = 0.221–0.297) ind.•m–2 among the beds. Shell size compositions differed significantly despite the relative proximity of the beds. Weathervane density was positively related (in order of influence) to gravel, shell debris, shell hash, mud, and cobble. Optical assessment of these five previously unsurveyed scallop beds in the Gulf of Alaska demonstrates the efficacy of this approach for weathervanes and suggests that the expansion of optical survey coverage to include other known beds as a viable path to overcoming the limitations of fishery-dependent information for scallop assessment and management in Alaskan waters.

Migratory Behavior of an Eastern North Pacific Gray Whale From Baja California Sur to Chirikov Basin, Alaska

Eastern gray whales undertake annual migrations between summer feeding grounds in the Bering and Chukchi Seas and winter breeding and calving lagoons in the west coast of Baja California, Mexico. On February 12, 2017, three adult gray whales were sighted at San José del Cabo, Mexico, in which one individual, named “María,” was tagged using a satellite telemetry transmitter (PTT). The PTT stopped the signal on July 11, 2017. María traveled 11,387 km during 149 days from San José del Cabo to the Chirikov Basin. The migration route was aligned close to the coastline (<23 km) from February to April. After passing Kodiak Island in May, María started traveling far away from the coastline (>70 km) into the Bering Sea, including the Chirikov Basin. During March, April, and May, María traveled long distances at relatively high speeds, in contrast to the lower speed during February, early March, and the arrival time to the feeding areas in May, June, and July. The total distance traveled by María during its migration from Ojo de Liebre Lagoon to the Chirikov Basin was 8,863 km during 61.5 days with an average speed of 5.5 km h–1; this excludes the 14 days and 591 km that María spent feeding on the coast of Kodiak Island in late April. The information provided by this tagged whale documents a single whales’ migration, which is consistent with previous studies and constitutes the most complete northbound reported migration of an eastern gray whale.

The 1900 Mw 7.6–8.0 Earthquake Offshore of Kodiak Island, Alaska

The 1900 Mw 7.6–8.0 Earthquake Offshore of Kodiak Island, Alaska

Subducting oceanic basement roughness impacts on upper-plate tectonic structure and a backstop splay fault zone activated in the southern Kodiak aftershock region of the Mw 9.2, 1964 megathrust rupture, Alaska

AbstractIn 1964, the Alaska margin ruptured in a giant Mw 9.2 megathrust earthquake, the second largest during worldwide instrumental recording. The coseismic slip and aftershock region offshore Kodiak Island was surveyed in 1977–1981 to understand the region’s tectonics. We re-processed multichannel seismic (MCS) field data using current standard Kirchhoff depth migration and/or MCS traveltime tomography. Additional surveys in 1994 added P-wave velocity structure from wide-angle seismic lines and multibeam bathymetry. Published regional gravity, backscatter, and earthquake compilations also became available at this time.Beneath the trench, rough oceanic crust is covered by ∼3–5-km-thick sediment. Sediment on the subducting plate modulates the plate interface relief. The imbricate thrust faults of the accreted prism have a complex P-wave velocity structure. Landward, an accelerated increase in P-wave velocities is marked by a backstop splay fault zone (BSFZ) that marks a transition from the prism to the higher rigidity rock beneath the middle and upper slope. Structures associated with this feature may indicate fluid flow. Farther upslope, another fault extends >100 km along strike across the middle slope. Erosion from subducting seamounts leaves embayments in the frontal prism.Plate interface roughness varies along the subduction zone. Beneath the lower and middle slope, 2.5D plate interface images show modest relief, whereas the oceanic basement image is rougher. The 1964 earthquake slip maximum coincides with the leading and/or landward flank of a subducting seamount and the BSFZ. The BSFZ is a potentially active structure and should be considered in tsunami hazard assessments.

Alutiiq Ancestors’ Use of Birds During the Ocean Bay Period at Rice Ridge (49-KOD-363), Kodiak Island, Alaska

Alutiiq Ancestors’ Use of Birds During the Ocean Bay Period at Rice Ridge (49-KOD-363), Kodiak Island, Alaska

Differing prey associations and habitat use suggest niche partitioning by fin and humpback whales off Kodiak Island

FinBalaenoptera physalusand humpbackMegaptera novaeangliaewhales share foraging areas and may compete for the same prey, but little is known about the extent to which they partition prey resources. Visual cetacean surveys and simultaneous acoustic-trawl surveys of prey were conducted around 2 submarine canyons off Kodiak Island, Alaska, in 2004 and 2006. Statistical models were used to examine the associations between sightings of fin and humpback whales and measures of their potential prey and environment. Observations and models indicate that fin whales were disproportionately abundant in areas with the highest observed euphausiid concentrations, while humpback whales were abundant at lower euphausiid concentrations and in areas where juvenile walleye pollock were abundant. Fin whales were abundant in the areas where euphausiid biomass was deepest and in the deepest areas surveyed (>150 m depth). In contrast, humpback whales primarily occurred in shallower areas and near more shallowly distributed euphausiids. The different depth and prey affinities of fin and humpback whales suggest niche and habitat partitioning between these 2 co-occurring species. Abundance models built using acoustic estimates of prey density are a useful tool to further understanding of the abundance, distribution, and behavior of these animals.

The Alaska Amphibious Community Seismic Experiment

AbstractThe Alaska Amphibious Community Seismic Experiment (AACSE) is a shoreline-crossing passive- and active-source seismic experiment that took place from May 2018 through August 2019 along an ∼700 km long section of the Aleutian subduction zone spanning Kodiak Island and the Alaska Peninsula. The experiment featured 105 broadband seismometers; 30 were deployed onshore, and 75 were deployed offshore in Ocean Bottom Seismometer (OBS) packages. Additional strong-motion instruments were also deployed at six onshore seismic sites. Offshore OBS stretched from the outer rise across the trench to the shelf. OBSs in shallow water (<262 m depth) were deployed with a trawl-resistant shield, and deeper OBSs were unshielded. Additionally, a number of OBS-mounted strong-motion instruments, differential and absolute pressure gauges, hydrophones, and temperature and salinity sensors were deployed. OBSs were deployed on two cruises of the R/V Sikuliaq in May and July 2018 and retrieved on two cruises aboard the R/V Sikuliaq and R/V Langseth in August–September 2019. A complementary 398-instrument nodal seismometer array was deployed on Kodiak Island for four weeks in May–June 2019, and an active-source seismic survey on the R/V Langseth was arranged in June 2019 to shoot into the AACSE broadband network and the nodes. Additional underway data from cruises include seafloor bathymetry and sub-bottom profiles, with extra data collected near the rupture zone of the 2018 Mw 7.9 offshore-Kodiak earthquake. The AACSE network was deployed simultaneously with the EarthScope Transportable Array (TA) in Alaska, effectively densifying and extending the TA offshore in the region of the Alaska Peninsula. AACSE is a community experiment, and all data were made available publicly as soon as feasible in appropriate repositories.

Examination of saffron cod Eleginus gracilis (Tilesius 1810) population genetic structure

Annual ice retreat in the northern Bering and Chukchi seas, which has occurred earlier in the past decades resulting in longer ice-free seasons and warmer ocean temperatures, is producing a cascade of ecological effects, and may open Arctic waters to commercial fishing and oil exploration. Baseline knowledge of population structure of a species is critical to developing strategies for management and conservation. There is little information for the saffron cod (Eleginus gracilis), an abundant forage fish inhabiting the coastlines of the North Pacific and Arctic oceans. We examined saffron cod population genetic structure with data from nine microsatellite loci designed to describe the genetic compositions of and variation among 40 collections of saffron cod from four regions (northwestern Alaska, Gulf of Alaska, western Pacific Ocean, and Gulf of Anadyr). The northwestern Alaska collections (Norton Sound and Chukchi Sea) exhibited little genetic divergence. The Gulf of Anadyr collection differed from other regions but was most similar to those of northwestern Alaska. The collections from the western Pacific Ocean (Sakhalin Island and Hokkaido Island) differed genetically, but not to the extent they did from other regions. Gulf of Alaska collections (Kodiak Island and Prince William Sound) comprised a lineage that was distinct from all of the other areas, including the geographically adjacent northwestern Alaska collections. The absence of genetic structure in northwestern Alaska probably reflects their recent expansion into previously unavailable habitat that became available after the Last Glacial Maximum (~ 16,000 years ago). Tracking and predicting the likely expansion of the eurythermal saffron cod may have parallels to its postglacial colonization.

Natives and Creoles of Alaska in the maritime service in Russian America

ABSTRACT In the initial stage of Russian colonization of Alaska, very few Natives were involved in carrying out maritime service on Russian ships, as they lacked some of the required qualifications and skills. Only after the Russians had established the first permanent settlement on Kodiak Island in 1784 were some Natives drawn into maritime service, though in a limited number. From the beginning of the nineteenth century, Natives came to be replaced more and more by Creoles (people of mixed European and indigenous descent), who, toward the middle of the century, made up a substantial part of the crew on ships of the Russian-American Company (RAC), which managed the Alaska colony from 1799 until its sale to the United States in 1867. Many Creoles were prepared from childhood to carry out maritime service, serving initially as cabin boys. The most capable Creoles were sent to Kronstadt and St. Petersburg for training, after which they were returned to the Russian colonies in the New World as certified maritime specialists. By the end the Russian-America period, one-third to one-half of the navigators, first mates, and skippers who commanded RAC ships were Creoles. Among those native to Alaska, it was the Creoles who played the most significant role in the maritime history of Russian America and the geographic discoveries in its territory.

The adoption of pottery on Kodiak Island: Insights from organic residue analysis

Pottery technology, originating in Northeast Asia, appeared in Alaska some 2800 years ago. It spread swiftly along Alaska's coastline but was not adopted on Kodiak Island until around 500 cal BP, as part of the Koniag tradition. While in the southeast pottery was used extensively, people on the northern half of the island did not adopt the technology. What drove these patterns of adoption and non-adoption on Kodiak Island? To better understand the role of ceramic technology in the Koniag tradition we used organic residue analysis to investigate pottery function. Results indicate that pottery was used to process aquatic resources, including anadromous fish, but especially marine species. Based on archaeological and ethnographic data, and spatial analysis of pottery distributions and function, we hypothesize that Koniag pottery was a tool inherent to the rendering of whale oil on the southeast coast of Kodiak Island, supporting previous suggestions by Knecht (1995) and Fitzhugh (2001). When viewed in the broader historical context of major technological and social transformations, we conclude that social identity and cultural boundaries may also have played a role in the delayed and partial adoption of pottery on Kodiak Island.

Effect on Subduction of Deeply Buried Seamounts Offshore of Kodiak Island

AbstractSeamounts are ubiquitous on the oceanic plate; those situated near convergent margins will eventually undergo subduction. Using six prestack depth migrated MCS profiles transecting the Aleutian Trench, we investigate deeply buried seamounts offshore Kodiak Island, within 145–155°W and 55–58°N. A distinct sedimentary horizon exists in all six seismic profiles, at or above the average height of seamounts, which appears to be the preferred structural detachment zone. Where drilled, this horizon contains gravel‐sized debris interpreted to be ice rafted and marks the onset of intensification of Northern Hemisphere glaciation at ~2.7 Ma. Beneath this horizon, sediments prior to the Surveyor Fan development were deposited, all or the majority of these sediments will eventually be subducted. Despite the subducted seamounts being deeply buried, these features cause enhanced surface slope of the accretionary prism. Our observations lead us to propose a model for the stages of subduction for deeply buried seamounts. These stages include the following: (1) Prior to subduction, the protothrust zone undergoes enhanced shortening, (2) frontal thrust steepening and enhanced backthrusting occurs during subduction with a potential décollement step down seaward and a steeping outward of the deformation front to the limit of the protothrust zone, and (3) further subduction results in a pattern of uplift farther into the wedge resulting in enhanced out‐of‐sequence thrusting and persistence of the more seaward deformation front position. This pattern is distinct from the dominance of embayments and effective removal of prism material during seamount subduction described along margins with less deeply buried edifices.

Near‐Field Modeling of the 1964 Alaska Tsunami: The Role of Splay Faults and Horizontal Displacements

AbstractNear‐field observations of tsunami waves generated by the Mw9.2 1964 Alaska earthquake reveal a complex relationship between coseismic slip and the tsunami wavefield in the source area. The documented times and amplitudes of first arrivals, measured run‐up heights and inundation areas along the coasts of the Kenai Peninsula and Kodiak Island show that secondary splay faults played an important role in generating destructive tsunami waves. We find that a splay fault extending to about 150°W is required to fit tsunami first arrivals on the Kenai Peninsula but that the splay fault did not rupture along the entire length of the Kenai Peninsula. This extent supports the connection of splay faulting to a persistent Prince William Sound asperity. Our results also show that the contribution of coseismic horizontal displacements into the initial tsunami wavefield does not change the pattern of tsunami arrivals much but increases the amplitude. The coseismic deformation model of Suito and Freymueller (2009, https://doi.org/10.1029/2008JB005954) explains the pattern of tsunami arrivals in the Kodiak Island region well, indicating that it provides a good estimate of slip on the megathrust in the Kodiak asperity. The sensitivity of the near‐field arrival information to the coseismic slip model shows that such data are important in distinguishing between slip on splay faults and on the megathrust and in discriminating between competing slip models.

Model‐based clustering reveals patterns in central place use of a marine top predator

AbstractSatellite telemetry data are commonly used to quantify habitat selection, examine animal movements, and delineate home ranges. These data also contain valuable information concerning dens, nests, roosts, and other central places that are often associated with important life history events and may exhibit unique characteristics; however, using satellite telemetry data to study central places is complicated by common nuances like locational error and animal movement. We coupled a novel modeling framework that accounts for these nuances with an Argos satellite telemetry dataset to examine the spatiotemporal behavior associated with harbor seal haul‐out sites on Kodiak Island, Alaska, USA. The methodology incorporates an observation model that accommodates multiple sources of uncertainty in telemetry data and a flexible Bayesian nonparametric model to uncover latent clustering in the telemetry locations. We also contribute extensions to examine the effect of covariates on site selection and to obtain population‐level inference concerning central place use. Harbor seal haul‐out sites generally occurred in inlets and bays, areas that are isolated from the open water of the Gulf of Alaska. Most individuals selected haul‐out sites that were protected from wave exposure. The effects of bathymetry and shoreline complexity on haul‐out site selection were variable among individual seals, as were the effects of time of day, time since low tide, and day of year on temporal patterns of haul‐out use. As repositories of satellite telemetry data on a wide variety of species accumulate, so do opportunities for using this information to learn about the locations of central places, as well as the temporal patterns in their use. The model‐based approach we describe offers a practical and rigorous means for gaining insight concerning these sensitive locations, knowledge of which is important for the effective management and conservation of many species.

The January 23, 2018 M7.9 Kodiak earthquake, Alaska: A consequence of slip partitioning in the outer rise region

The January 23, 2018 M7.9 earthquake ruptured conjugate set of strike-slip faults in the outer rise of the Alaska subduction zone, southeast of Kodiak Island. The complex nature of this earthquake is evident from the earthquake focal mechanism and aftershock relocation patterns which revealed rupture of multiple north-south and east-west trending conjugate fault planes. Here, we suggest that this earthquake occurred as a result of two different modes of interaction process. The stress triggering process reveals (i) the co-seismic and post-seismic deformation of the M9.2 1964 Alaska megathrust earthquake increased Coulomb failure stress of ∼10 kPa and ∼0.05 kPa respectively in the 2018 Kodiak earthquake source region, and (ii) the overall deformation is being accommodated in the outer rise region due to slip partitioning resulting from the oblique convergence between the Pacific and North American plates along the Alaska Aleutian megathrust.