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At least 865 records · Page 48Linked to original sources
USGS2013

New imaging of submarine landslides from the 1964 earthquake near Whittier, Alaska, and a comparison to failures in other Alaskan fjords

The 1964 Alaska M w 9.2 earthquake triggered numerous submarine slope failures in fjords of southern Alaska. These failures generated local tsunamis, such as at Whittier, where they inundated the town within 4 min of the beginning of shaking. Run-up was up to 32 m, with 13 casualties. We collected new multibeam bathymetry and high-resolution sparker seismic data in Passage Canal, and we examined bathymetry changes before and after the earthquake. The data reveal the debris flow deposit from the 1964 landslides, which covers the western 5 km of the fjord bottom. Individual blocks in the flow are up to 145-m wide and 25-m tall. Bathymetry changes show the mass transfer deposits originated from the fjord head and Whittier Creek deltas and had a volume of about 42 million m 3 . The 1964 deposit has an average thickness of ∼5.4 m. Beyond the debris flow, the failures likely deposited a ∼4.6-m thick megaturbidite in a distal basin. We have studied the 1964 submarine landslides in three fjords. All involved failure of the fjord-head delta. All failures eroded basin-floor sediments and incorporated them as they travelled. All the failures deposited blocks, but their size and travel distances varied greatly. We find a correlation between maximum block size and maximum tsunami run-up regardless of the volume of the slides. Lastly, the fjord’s margins were influenced by increased supply of glacial sediments during the little ice age, which along with a long interseismic interval (∼900 years) may have caused the 1964 earthquake to produce particularly numerous and large submarine landslides.

Alaska↗
USGS2022

Landslides triggered by the 2002 M 7.9 Denali Fault earthquake, Alaska, USA

The 2002 M 7.9 Denali earthquake in Alaska, USA, was the largest inland earthquake in North America in nearly 150 years. The earthquake involved oblique thrusting but mostly strike-slip motion, and faults ruptured the ground surface over 330 km. Fault rupture occurred in a rugged, mountainous, subarctic environment with extensive permafrost and variable glaciation, geology, and groundwater presence, and many triggered landslides mobilized into avalanches that traversed varied physiographic settings, some moving farther than 11 km. However, only several thousand landslides were triggered, and these occurred in a narrow zone along the fault rupture. These characteristics of the event provide ample opportunities to improve understanding of controls on coseismic landsliding and avalanching mechanisms. The paucity and limited extent of landslides likely resulted from high directivity of seismic energy and relatively low levels of high-amplitude, high-frequency ground motion; glacial damping of seismic energy was likely not a factor. Landslides preferentially occurred on hillslopes steeper and higher than average. Meteorological conditions were near historical averages at the time of the event, although the region has experienced gradual warming historically that appears to have resulted in increased landslide occurrence in other parts of Alaska during recent years. Inherent susceptibility of geological formations to landsliding was not apparent with the available data, although discontinuities created dip-slope conditions for the five largest slides. Historical thinning of glaciers and consequent slope debuttressing may have been a factor in aiding occurrence of some of the earthquake-induced landslides, particularly some of the largest. Mobility of the largest avalanches was above average compared to global data, and mobility of all sizes of avalanches was apparently aided by movement over glacial ice. Avalanche deposits displayed characteristics indicative of turbulent flow on steeper slopes and laminar plug flow in flatter areas, where sliding also likely occurred.

Alaska↗
USGS1992

The study of the undiscovered mineral resources of the Tongass National Forest and adjacent lands, Southeastern Alaska

The quantitative probabilistic assessment of the undiscovered mineral resources of the 17.1-million-acre Tongass National Forest (the largest in the United States) and its adjacent lands is a nonaggregated, mineral-resource-tract-oriented assessment designed for land-planning purposes. As such, it includes the renewed use of gross-in-place values (GIPV's) in dollars of the estimated amounts of metal contained in the undiscovered resources as a measure for land-use planning. Southeastern Alaska is geologically complex and contains a wide variety of known mineral deposits, some of which have produced important amounts of metals during the past 100 years. Regional geological, economic geological, geochemical, geophysical, and mineral exploration history information for the region was integrated to define 124 tracts likely to contain undiscovered mineral resources. Some tracts were judged to contain more than one type of mineral deposit. Each type of deposit may contain one or more metallic elements of economic interest. For tracts where information was sufficient, the minimum number of as-yet-undiscovered deposits of each type was estimated at probability levels of 0.95, 0.90, 0.50, 0.10, and 0.05. The undiscovered mineral resources of the individual tracts were estimated using the U.S. Geological Survey's MARK3 mineral-resource endowment simulator; those estimates were used to calculate GIPV's for the individual tracts. Those GIPV's were aggregated to estimate the value of the undiscovered mineral resources of southeastern Alaska. The aggregated GIPV of the estimates is $40.9 billion. Analysis of this study indicates that (1) there is only a crude positive correlation between the size of individual tracts and their mean GIPV's: and (2) the number of mineral-deposit types in a tract does not dominate the GIPV's of the tracts, but the inferred presence of synorogenic-synvolcanic nickel-copper, porphyry copper skarn-related, iron skarn, and porphyry copper-molybdenum deposits does. The influence of this study on the U.S. Forest Service planning process is yet to be determined. ?? 1992 Oxford University Press.

Nonrenewable Resources↗
USGS1984

Heavy minerals in surficial sediments from lower Cook Inlet, Alaska

Amphiboles, orthopyroxenes, and clinopyroxenes dominate the heavy mineral suite of surficial sediments in lower Cook Inlet, Alaska. Sources for these sediments include the igneous arc terrane of the northeast Alaska Range, reworked intrabasinal sediments, and local drainages in lower Cook Inlet. The distribution of these deposits is a reflection of both the tidal currents and the prevailing southerly net movement from the head of Cook Inlet. The heavy mineral studies concur with similar findings from gravel analyses, clay mineral investigations, and quartz microtexture observations. ?? 1984 Springer-Verlag New York Inc.

Geo-Marine Letters↗
USGS1984

Trench-fill submarine-fan facies associations of the Upper Cretaceous Chugach terrane, southern Alaska

Turbidites of the Upper Cretaceous Chugach terrane of southern Alaska were deposited in a trench during northward-directed subduction. The fault-bounded outcrop belt of the Chugach terrane is about 2000-km long and 100-km wide and was accreted to Alaska during the Cenozoic. Turbidites are at least 5000 m thick, are extensively deformed, have been regionally metamorphosed, and have been intruded by anatectic granites. Facies associations indicate an east-to-west progression from inner-fan to middle-fan, outer-fan, fan-fringe, and basin-plain deposits. To the north is a marginal trench-slope facies association and a basin. ?? 1984 Springer-Verlag New York Inc.

Geo-Marine Letters↗
USGS2010

Combined effects of tectonic and landslide-generated Tsunami Runup at Seward, Alaska during the Mw 9.2 1964 earthquake

We apply a recently developed and validated numerical model of tsunami propagation and runup to study the inundation of Resurrection Bay and the town of Seward by the 1964 Alaska tsunami. Seward was hit by both tectonic and landslide-generated tsunami waves during the M W "> M W MW 9.2 1964 megathrust earthquake. The earthquake triggered a series of submarine mass failures around the fjord, which resulted in landsliding of part of the coastline into the water, along with the loss of the port facilities. These submarine mass failures generated local waves in the bay within 5 min of the beginning of strong ground motion. Recent studies estimate the total volume of underwater slide material that moved in Resurrection Bay to be about 211 million m 3 (Haeussler et al. in Submarine mass movements and their consequences, pp 269–278, 2007 ). The first tectonic tsunami wave arrived in Resurrection Bay about 30 min after the main shock and was about the same height as the local landslide-generated waves. Our previous numerical study, which focused only on the local landslide-generated waves in Resurrection Bay, demonstrated that they were produced by a number of different slope failures, and estimated relative contributions of different submarine slide complexes into tsunami amplitudes (Suleimani et al. in Pure Appl Geophys 166:131–152, 2009 ). This work extends the previous study by calculating tsunami inundation in Resurrection Bay caused by the combined impact of landslide-generated waves and the tectonic tsunami, and comparing the composite inundation area with observations. To simulate landslide tsunami runup in Seward, we use a viscous slide model of Jiang and LeBlond (J Phys Oceanogr 24(3):559–572, 1994 ) coupled with nonlinear shallow water equations. The input data set includes a high resolution multibeam bathymetry and LIDAR topography grid of Resurrection Bay, and an initial thickness of slide material based on pre- and post-earthquake bathymetry difference maps. For simulation of tectonic tsunami runup, we derive the 1964 coseismic deformations from detailed slip distribution in the rupture area, and use them as an initial condition for propagation of the tectonic tsunami. The numerical model employs nonlinear shallow water equations formulated for depth-averaged water fluxes, and calculates a temporal position of the shoreline using a free-surface moving boundary algorithm. We find that the calculated tsunami runup in Seward caused first by local submarine landslide-generated waves, and later by a tectonic tsunami, is in good agreement with observations of the inundation zone. The analysis of inundation caused by two different tsunami sources improves our understanding of their relative contributions, and supports tsunami risk mitigation in south-central Alaska. The record of the 1964 earthquake, tsunami, and submarine landslides, combined with the high-resolution topography and bathymetry of Resurrection Bay make it an ideal location for studying tectonic tsunamis in coastal regions susceptible to underwater landslides.

Alaska↗
USGS2016

A possible source mechanism of the 1946 Unimak Alaska far-field tsunami, uplift of the mid-slope terrace above a splay fault zone

In 1946, megathrust seismicity along the Unimak segment of the Alaska subduction zone generated the largest ever recorded Alaska/Aleutian tsunami. The tsunami severely damaged Pacific islands and coastal areas from Alaska to Antarctica. It is the charter member of “tsunami” earthquakes that produce outsized far-field tsunamis for the recorded magnitude. Its source mechanisms were unconstrained by observations because geophysical data for the Unimak segment were sparse and of low resolution. Reprocessing of legacy geophysical data reveals a deep water, high-angle reverse or splay thrust fault zone that leads megathrust slip upward to the mid-slope terrace seafloor rather than along the plate boundary toward the trench axis. Splay fault uplift elevates the outer mid-slope terrace and its inner area subsides. Multibeam bathymetry along the splay fault zone shows recent but undated seafloor disruption. The structural configuration of the nearby Semidi segment is similar to that of the Unimak segment, portending generation of a future large tsunami directed toward the US West coast.

Alaska↗
USGS2009

Does winter region affect spring arrival time and body mass of king eiders in northern Alaska?

Events during the non-breeding season may affect the body condition of migratory birds and influence performance during the following breeding season. Migratory birds nesting in the Arctic often rely on endogenous nutrients for reproductive efforts, and are thus potentially subject to such carry-over effects. We tested whether king eider ( Somateria spectabilis ) arrival time and body mass upon arrival at breeding grounds in northern Alaska were affected by their choice of a winter region in the Bering Sea. We captured birds shortly after arrival on breeding grounds in early June 2002–2006 at two sites in northern Alaska and determined the region in which individuals wintered using satellite telemetry or stable isotope ratios of head feathers. We used generalized linear models to assess whether winter region explained variation in arrival body mass among individuals by accounting for sex, site, annual variation, and the date a bird was captured. We found no support for our hypothesis that either arrival time or arrival body mass of king eiders differed among winter regions. We conclude that wintering in different regions in the Bering Sea is unlikely to have reproductive consequences for king eiders in our study areas.

Alaska↗
USGS2013

Genetics, recruitment, and migration patterns of Arctic Cisco (Coregonus autumnalis) in the Colville River, Alaska and Mackenzie River, Canada

Arctic cisco Coregonus autumnalis have a complex anadromous life history, many aspects of which remain poorly understood. Some life history traits of Arctic cisco from the Colville River, Alaska, and Mackenzie River basin, Canada, were investigated using molecular genetics, harvest data, and otolith microchemistry. The Mackenzie hypothesis, which suggests that Arctic cisco found in Alaskan waters originate from the Mackenzie River system, was tested using 11 microsatellite loci and a single mitochondrial DNA gene. No genetic differentiation was found among sample collections from the Colville River and the Mackenzie River system using molecular markers (P > 0.19 in all comparisons). Model-based clustering methods also supported genetic admixture between sample collections from the Colville River and Mackenzie River basin. A reanalysis of recruitment patterns to Alaska, which included data from recent warm periods and suspected changes in atmospheric circulation patterns, still finds that recruitment is correlated to wind conditions. Otolith microchemistry (Sr/Ca ratios) confirmed repeated, annual movements of Arctic cisco between low-salinity habitats in winter and marine waters in summer.

Polar Biology↗
USGS2014

Quantifying fall migration of Ross's gulls (Rhodostethia rosea) past Point Barrow, Alaska

The Ross’s gull ( Rhodostethia rosea ) is a poorly known seabird of the circumpolar Arctic. The only place in the world where Ross’s gulls are known to congregate is in the near-shore waters around Point Barrow, Alaska, where they undertake an annual passage in late fall. Ross’s gulls seen at Point Barrow are presumed to originate from nesting colonies in Siberia, but neither their origin nor their destination has been confirmed. Current estimates of the global population of Ross’s gulls are based largely on expert opinion, and the only reliable population estimate is derived from extrapolations from previous counts conducted at Point Barrow, but these data are now over 25 years old. In order to update and clarify the status of this species in Alaska, our study quantified the timing, number, and flight direction of Ross’s gulls passing Point Barrow in 2011. We recorded up to two-thirds of the estimated global population of Ross’s gulls (≥27,000 individuals) over 39 days with numbers peaking on 16 October when we observed over 7,000 birds during a 3-h period.

Alaska↗
USGS1999

Growth of a post-Little Ice Age submarine fan, Glacier Bay, Alaska

A small Holocene fan is forming where Queen Inlet, a hanging valley, enters West Arm fjord, Glacier Bay, Alaska. Queen fan formed in the last 80 years following retreat of the Little Ice Age glacier that filled Glacier Bay about 200 yr BP. It was built mainly by a turbidite system originating from Carroll Glacier delta, as the delta formed in the early 1900s at the head of Queen Inlet. The Late Holocene Queen fan is comparable to large Pleistocene fans that formed in the Gulf of Alaska and differs from trough-mouth fans formed by cooler climate glacier systems.

Geo-Marine Letters↗
USGS2020

Evolving infrasound detections from Bogoslof volcano, Alaska: Insights from atmospheric propagation modeling

Bogoslof volcano, a back-arc volcano in Alaska’s Aleutian arc, began an eruptive sequence in mid-December 2016 that ended in late August 2017, with 70 individual eruptive episodes. Because there were no local seismic or infrasound stations on the island, the Alaska Volcano Observatory (AVO) relied on distant geophysical networks and remote sensing techniques to assess activity during the eruption. AVO maintains six infrasound arrays to monitor activity along the Aleutian arc: Adak, the Island of Four Mountains, Okmok, Akutan, Sand Point, and Dillingham. Eruption detection at infrasound arrays is subject to local as well as mesoscale meteorological conditions that vary greatly over both short and long timescales. Infrasound detections from the array nearest to Bogoslof (Okmok), with a latency of about 3 min, played a crucial role in monitoring activity during the eruption. Despite the relative proximity of the Okmok array to Bogoslof (60 km), infrasound detections were not uniformly observed with only about two-thirds of the events successfully detected. The farthest array at Dillingham (816 km) detected approximately half of the explosive events, with all other arrays detecting less than half of the events. We compare observations with infrasound propagation model predictions, using both normal mode and parabolic equation forward models, to interpret the variation in detections of the 70 explosive events across the AVO infrasound network. The forward models utilize the newly created, publicly available AVO-G2S atmospheric reconstruction using numerical weather predictions data for the lower atmosphere, coupled with upper atmosphere empirical models of wind speeds and temperature. We find that long-range detections (> 100 km) of Bogoslof events are largely aligned with seasonal variability in favorable propagation conditions, while regional detections (< 100 km) are less consistent with propagation modeling. Understanding the output of numerical models in comparison to past observations will facilitate their use in future operational settings for AVO and other observatories.

Alaska↗
USGS2024

From field station to forecast: Managing data at the Alaska Volcano Observatory

The Alaska Volcano Observatory (AVO) uses multidisciplinary data to monitor and study dozens of active and potentially active volcanoes. Here, we provide an overview of internally and externally generated data types, tools and resources used in their management, and challenges faced. Data sources include the following: (1) a multiparameter (seismic, infrasound, GNSS, web cameras) ground-based monitoring network that spans 3000 km and transmits data in real time; (2) a variety of satellite-borne sensors that provide information about surface change and volcanic emissions; (3) geologic and gas field campaigns; and (4) other external data products that provide situation awareness. Each data type requires distinct acquisition, processing, storage, visualization, and archiving approaches. AVO uses a variety of externally and internally developed tools to handle individual data types as well as multidisciplinary volcanological data. A primary tool is the Geologic Database of Information on Volcanoes in Alaska (GeoDIVA), which stores detailed, searchable information on more than 140 volcanoes and over 1000 eruptions and unrest events, including images, eruption descriptions, and geologic station and sample data, metadata, and analyses. It interacts with other internal tools that store monitoring reports and other operational records. Additional data management resources used by AVO assist with alarms and alerts, state-of-health monitoring, and multiparameter visualization. Requirements for 24/7 accessibility, the ever-expanding portfolio of data, and transitioning new tools from development to operations are all challenges faced by AVO and other volcano observatories. AVO strives to meet FAIR data practices and ensure that data are available to national and international community efforts using external repositories as well as those hosted by AVO and its parent institutions.

Alaska↗
USGS2025

Mount Spurr volcano, August 18, 1992: The eruption heard around Alaska

The August 18, 1992, eruption of Mount Spurr volcano, Alaska, produced an impressive Vulcanian to Subplinian eruption column reaching up to 40 km above sea level that blanketed the nearby city of Anchorage with ash. At the time of the eruption, the Alaska Volcano Observatory received reports of audible sound hundreds of kilometers from the source from a variety of azimuths from the volcano and found the pattern that did not solely depend on distance. Explosions are generally inaudible to the human ear at these distances due to the attenuation of sound in the atmosphere as the energy propagates, but low-frequency sound waves (infrasound) persist and can be used to detect and characterize eruptions. Similar reports of zones of audible sounds at great distances have been observed from notable eruptions such as Krakatau 1883, Mount St. Helens 1980, Mount Pinatubo 1991, and Hunga volcano 2022. We perform infrasound propagation modeling to help understand the unique distribution of audible reports, finding that areas with favorable infrasound propagation may help explain areas in which nonlinear propagation, including energy cascading effects into higher frequencies that are audible to the human ear, may have occurred.

Alaska↗
USGS2026

Examples of eruption response teams from the Alaska Volcano Observatory

During times of eruption response, volcano observatories need to organize themselves differently than during normal operations. The number of formal operational roles grows to ensure that critical responsibilities are covered, including management of all activities at the observatory as well as increased staffing to ensure proper surveillance of data and issuance of timely notices and warnings. The scope and approach differ for each observatory and, in fact, for different eruptions. The Alaska Volcano Observatory (AVO) maintains an extensive monitoring program and issues forecasts and warnings about volcanic eruptions and unrest in Alaska. Since 2000, AVO has used formal roles to perform these duties and has implemented a variety of team approaches to respond to larger eruptions. For the Augustine (2006) and Redoubt (2009) eruptions, management scaled from 3 up to ~ 8 people in a command team to cover all aspects of the response. During these and other eruptions (e.g., Okmok, 2008), an operations room was staffed continuously to cover real-time responsibilities pertaining to monitoring and issuing alerts while the command team focused on overall management. More recently, such as for Bogoslof in 2016–2017 and Shishaldin in 2019 and 2023, AVO used a virtual real-time response team to handle warning tasks and variations of an Observatory Volcanic Event Response Team (OVERT; Moran et al. 2024) to manage overall observatory response activities. In 2025, AVO employed a formal OVERT for the first time to oversee its response to unrest at Mount Spurr. Frequent implementation, nimble scaling, constant evaluation, flexibility, and good communication make the team approach effective. We present examples of several response teams used over the last 25 years, and lessons learned from them, in the hope that these will be helpful to other observatories facing crisis responses. These examples may also allow stakeholders and the public to better understand how observatories work.

Alaska↗
USGS2008

Recovery of aboveground plant biomass and productivity after fire in mesic and dry black spruce forests of interior Alaska

Plant biomass accumulation and productivity are important determinants of ecosystem carbon (C) balance during post-fire succession. In boreal black spruce (Picea mariana) forests near Delta Junction, Alaska, we quantified aboveground plant biomass and net primary productivity (ANPP) for 4 years after a 1999 wildfire in a well-drained (dry) site, and also across a dry and a moderately well-drained (mesic) chronosequence of sites that varied in time since fire (2 to ???116 years). Four years after fire, total biomass at the 1999 burn site had increased exponentially to 160 ?? 21 g m-2 (mean ?? 1SE) and vascular ANPP had recovered to 138 ?? 32 g m-2 y -1, which was not different than that of a nearby unburned stand (160 ?? 48 g m-2 y-1) that had similar pre-fire stand structure and understory composition. Production in the young site was dominated by re-sprouting graminoids, whereas production in the unburned site was dominated by black spruce. On the dry and mesic chronosequences, total biomass pools, including overstory and understory vascular and non-vascular plants, and lichens, increased logarithmically (dry) or linearly (mesic) with increasing site age, reaching a maximum of 2469 ?? 180 (dry) and 4008 ?? 233 g m-2 (mesic) in mature stands. Biomass differences were primarily due to higher tree density in the mesic sites because mass per tree was similar between sites. ANPP of vascular and non-vascular plants increased linearly over time in the mesic chronosequence to 335 ?? 68 g m-2 y -1 in the mature site, but in the dry chronosequence it peaked at 410 ?? 43 g m-2 y-1 in a 15-year-old stand dominated by deciduous trees and shrubs. Key factors regulating biomass accumulation and production in these ecosystems appear to be the abundance and composition of re-sprouting species early in succession, the abundance of deciduous trees and shrubs in intermediate aged stands, and the density of black spruce across all stand ages. A better understanding of the controls over these factors will help predict how changes in climate and fire regime will affect the carbon balance of Interior Alaska. ?? 2008 Springer Science+Business Media, LLC.

Ecosystems↗
USGS2008

Interactive effects of fire, soil climate, and moss on CO 2 fluxes in black spruce ecosystems of interior Alaska

Fire is an important control on the carbon (C) balance of the boreal forest region. Here, we present findings from two complementary studies that examine how fire modifies soil organic matter properties, and how these modifications influence rates of decomposition and C exchange in black spruce (Picea mariana) ecosystems of interior Alaska. First, we used laboratory incubations to explore soil temperature, moisture, and vegetation effects on CO 2 and DOC production rates in burned and unburned soils from three study regions in interior Alaska. Second, at one of the study regions used in the incubation experiments, we conducted intensive field measurements of net ecosystem exchange (NEE) and ecosystem respiration (ER) across an unreplicated factorial design of burning (2 year post-fire versus unburned sites) and drainage class (upland forest versus peatland sites). Our laboratory study showed that burning reduced the sensitivity of decomposition to increased temperature, most likely by inducing moisture or substrate quality limitations on decomposition rates. Burning also reduced the decomposability of Sphagnum-derived organic matter, increased the hydrophobicity of feather moss-derived organic matter, and increased the ratio of dissolved organic carbon (DOC) to total dissolved nitrogen (TDN) in both the upland and peatland sites. At the ecosystem scale, our field measurements indicate that the surface organic soil was generally wetter in burned than in unburned sites, whereas soil temperature was not different between the burned and unburned sites. Analysis of variance results showed that ER varied with soil drainage class but not by burn status, averaging 0.9 ?? 0.1 and 1.4 ?? 0.1 g C m -2 d -1 in the upland and peatland sites, respectively. However, a more complex general linear model showed that ER was controlled by an interaction between soil temperature, moisture, and burn status, and in general was less variable over time in the burned than in the unburned sites. Together, findings from these studies across different spatial scales suggest that although fire can create some soil climate conditions more conducive to rapid decomposition, rates of C release from soils may be constrained following fire by changes in moisture and/or substrate quality that impede rates of decomposition. ?? 2008 Springer Science+Business Media, LLC.

Ecosystems↗
USGS2013

Review: groundwater in Alaska (USA)

Groundwater in the US state of Alaska is critical to both humans and ecosystems. Interactions among physiography, ecology, geology, and current and past climate have largely determined the location and properties of aquifers as well as the timing and magnitude of fluxes to, from, and within the groundwater system. The climate ranges from maritime in the southern portion of the state to continental in the Interior, and arctic on the North Slope. During the Quaternary period, topography and rock type have combined with glacial and periglacial processes to develop the unconsolidated alluvial aquifers of Alaska and have resulted in highly heterogeneous hydrofacies. In addition, the long persistence of frozen ground, whether seasonal or permanent, greatly affects the distribution of aquifer recharge and discharge. Because of high runoff, a high proportion of groundwater use, and highly variable permeability controlled in part by permafrost and seasonally frozen ground, understanding groundwater/surface-water interactions and the effects of climate change is critical for understanding groundwater availability and the movement of natural and anthropogenic contaminants.

Alaska↗