Geologically, the Arctic is one of the least-explored regions of Earth. Obtaining data in the high Arctic is logistically, economically, and environmentally expensive, but the township of Longyearbyen (population of 2617 as of 2024) at 78° N represents a relatively easily accessible gateway to Arctic geology and is home to The University Centre in Svalbard (UNIS). These unique factors provide a foundation from which to teach and explore Arctic geology via the classroom, the laboratory, and the field. UNIS was founded in 1993 as the Norwegian “field university”, offering field-based courses in Arctic geology, geophysics, biology, and technology to students from Norway and abroad. In this contribution, we present one of the educational components of the international collaboration project NOR-R-AM (a Norwegian-Russian-North American collaboration in Arctic research and collaboration, titled Changes at the Top of the World through Volcanism and Plate Tectonics) which ran from 2017 to 2024. One of the key deliverables of NOR-R-AM was a new graduate (Master's and PhD-level) course called Arctic Tectonics and Volcanism that we have established and taught annually at UNIS since 2018 and detail herein. The course's main objective is to teach the complex geological evolution of the Arctic from the Devonian period (∼ 420 million years ago, Ma) to the present day through integrating multi-scale datasets and a broad range of geoscientific disciplines. We outline the course itself before presenting student perspectives based on both an anonymous questionnaire (n=27) and in-depth perceptions of four selected students. The course, with an annual intake of up to 20 MSc and PhD students, is held over a 6-week period, typically in spring or autumn. The course comprises modules on field and polar safety, Svalbard/Barents Sea geology, wider Arctic geology, plate tectonics, mantle dynamics, geo- and thermochronology, and geochemistry of igneous systems. A field component, which in some years included an overnight expedition, provides an opportunity to appreciate Arctic geology and gather field observations and data. Digital outcrop models, photospheres, and tectonic plate reconstructions provide complementary state-of-the-art data visualization tools in the classroom and facilitate efficient fieldwork through pre-fieldwork preparation and post-fieldwork quantitative analyses. The course assessment is centred around an individual research project that is presented orally and in a short and impactful Geology journal-style article. Considering the complex subject and the diversity of students' backgrounds and level of geological knowledge before the course, the student experiences during this course demonstrate that the multi-disciplinary, multi-lecturer field-and-classroom teaching is efficient and increases their motivation to explore Arctic science.

Methane released from shelf regions is considered to be an important contributor to climate change. Knowledge of potential emissions from specific regions is therefore critical for estimating expected climate change. To this end, we use multichannel seismic data acquired in 2011 to image the subsurface and identify upwelling gas migration structures along the outer Chukchi Shelf in the Arctic Ocean. We examine the upper 2500 ms TWT of sediments for distinct sedimentary structures and anomalous seismic velocities. The data show a wide distribution of bright spots as a consequence of the fluid migration from deeper sources throughout the study area. However, no bottom simulating reflector is identified in the study area to indicate the base of a likely gas hydrate zone. Furthermore, high seismic velocities and strong ground reflectors are not observed, suggesting an absence of submarine permafrost from the outer Chukchi Shelf.

Abstract Knowledge about seafloor depth, or bathymetry, is crucial for various marine activities, including scientific research, offshore industry, safety of navigation, and ocean exploration. Mapping the central Arctic Ocean is challenging due to the presence of perennial sea ice, which limits data collection to icebreakers, submarines, and drifting ice stations. The International Bathymetric Chart of the Arctic Ocean (IBCAO) was initiated in 1997 with the goal of updating the Arctic Ocean bathymetric portrayal. The project team has since released four versions, each improving resolution and accuracy. Here, we present IBCAO Version 5.0, which offers a resolution four times as high as Version 4.0, with 100 × 100 m grid cells compared to 200 × 200 m. Over 25% of the Arctic Ocean is now mapped with individual depth soundings, based on a criterion that considers water depth. Version 5.0 also represents significant advancements in data compilation and computing techniques. Despite these improvements, challenges such as sea-ice cover and political dynamics still hinder comprehensive mapping.

In recent years, the Arctic Ocean has experienced a dramatic decrease in sea ice cover, leading to enhanced turbulent mixing and eddy activity. Due to the scarcity of high-resolution observations, our understanding of turbulent mixing in the Arctic is incomplete. Using three seismic reflection transects with high spatial resolution (similar to O (10) m) and concurrent ADCP-derived current velocity, this study identified 11 mesoscale eddies on the ice-free Chukchi Borderlands of the western Arctic Ocean. 82% of them are intra-halocline anticyclones. The total length of horizontal scales of these 11 eddies occupies similar to 40% of the total length of three seismic lines. Diapycnal diffusivities estimated from seismic data were enhanced and can be up to 10(-4) m(2) s(-1) at the edges of these eddies, compared with the average values (similar to 10(-6) m(2) s(-1)) at the Chukchi Borderlands. Seismic-estimated diffusivities were validated by fine-scale parameterization using ADCP-derived velocity data and historical hydrographic data. Enhanced diffusivities at the edges of eddies may be attributed to shear instabilities at the top and bottom edges and to submesoscale motions at the lateral edges of these eddies. We highlight the enhanced mixing at the edges of eddies in the halocline can increase the upward heat flux. This upward heat flux can transfer the heat of the warm Atlantic water below to the surface, which may further promote the melting of surface sea ice.

Halocline eddies transport mass and energy across the Arctic Ocean. Seismic oceanography uses multichannel seismic reflection (MCS) data to create high resolution images of the water column, revealing oceanic fine structures. In this paper, we present water column images processed from MCS data acquired during cruise MGL1112 on the Chukchi Borderlands in the western Arctic Ocean. Combined with along-track images of current velocities measured during MCS acquisition by a hull-mounted acoustic Doppler current profilers, a total of 23 mesoscale eddies were detected, of which 19 are anticyclonic, and 4 are cyclonic. They correspond to the lentoid and mounded reflections on the seismic images, respectively. These shallow eddies are constrained by the halocline and occur in regions with rugged seafloor. The geometric parameters of these eddies were estimated from the underway data collected during MGL1112. These parameters could be valuable for modeling 3D eddy structures and validating high-resolution climate projection models. Expendable Bathythermography (XBT) profiles of water temperature and sound speed versus depth were collected during this ruise. Three of the 24 XBT stations sampled eddies opportunely, we found one was warm-core and two were cold-core anticyclonic eddies combined with historical conductivity-temperature-depth data. The cores of these eddies might be made up of Pacific water. We synthesized the MCS records with coincident and historical hydrographic data which permitted distinctions between the seismic responses of the eddies. Distinctive reflection structures are observed around the eddy core (e.g., chaotic, imbricate, layered, and listric reflections), which could constrain stirring and mixing process of the eddies. These results are useful for better understanding the structure and evolution of the eddies on the Chukchi Borderlands and better understanding regional mass and energy transport processes in the western Arctic Ocean.

The up to 900 km broad shelves off East Siberia and northwest off Alaska, including the Chukchi Shelf and Borderland, are characterized by shallow water in the periphery of the Arctic Ocean, north of the Bering Strait. Seafloor investigations revealed the widespread presence of glacial bedforms, implying the former existence of grounded ice in this region. We discuss the erosion and deposition around and beneath ice sheets/shelves using a regional grid of 2D seismic reflection data, acquired in 2011 from R/V Marcus G. Langseth across the outer ~ 75 km of the Chukchi Shelf and the adjacent Chukchi Borderland. A high amplitude glacial base (GB) reflection extends over large parts of the shelf, separating glacial from preglacial strata. We define eleven seismic reflection characters, that we use to infer distinct depositional environments of glacial sediments. Thick well stratified sediments overlying the GB reflection in the south may have been impacted by fewer advance-retreat cycles than those near the northeastern and western shelf breaks. Here, the GB reflection pinches out at the seafloor next to reworked and eroded areas. Numerous meltwater channels, some up to several kilometers wide, together with grounding zone wedges and recessional moraines are hints for ice sheets in the Chukchi Region. These ice sheets built up a huge grounding zone wedge of 48 km × 75 km on the Chukchi Rise. More grounding zone wedges on the western sides of bathymetric highs of the Chukchi Borderland along with mega scale glacial lineations indicate later ice shelf advances from east during the late Quaternary. However, in the absence of deep sediment cores, the timing or origin of the ice grounding events cannot be fully reconstructed.

The Arctic Ocean is well-known for its large number of mesoscale eddies. We observed a lens-shaped mesoscale eddy by using two roughly perpendicular multichannel reflection seismic sections collected in the Northwind Basin, Arctic Ocean in late September 2011. This is the first seismic imaging of the water column in the Arctic Ocean. The two lines were acquired about seven days apart. The eddy had a horizontal scale of similar to 56 km and extended from near-surface to 300 m. The thickness of the eddy was similar to 250 m. The eddy core, characterized by weak reflections, has a radius of similar to 13 km. The volume of core water was similar to 89 km(3). The horizontal current velocity collected by acoustic Doppler current profiler simultaneously with the seismic data shows that the eddy had a rigid core with a rotation period of similar to 26 hr, and max azimuthal velocities of 0.59 m s(-1). The velocity outside the core decreased in a quadratic inverse curve with the radius. During the observation, the eddy moved westward with an advection velocity of similar to 1 cm s(-1), and the net transport of the core water was about 0.05 Sv. There were multi-arm structures at the boundaries of the eddy, forming submesoscale spiral bands. The steep spiral arms (dip angle can be up to similar to 4 degrees) may be caused by eddy stirring. Seismic observations provide important insights into our understanding of the vertical structure of ocean eddies, the horizontal and vertical transport of matter, and fluxes of heat that can cause sea ice melting in the Arctic Ocean.

Most of the Arctic region is contained within the territory of Norway, Russia, USA, Canada and Denmark/Greenland, yet the natural boundaries and processes do not conform to these political borders. This remote region requires special logistics, equipment and substantial financial support. The last decade has seen an increase in knowledge about the northern polar region for economic and political reasons, such as the extended continental shelf claims under UNCLOS and Arctic Council activities. It is crucial that scientific research, activities and their outcome are visible to the broader scientific community and communicated to the wider public. In recent years considerable effort has been invested by several groups and institutions to make various data and results available online and to use it for education and outreach. Examples include: the Arctic Observing Viewer which is a web mapping application in support of U.S. SEARCH, AON, SIOS, and other Arctic Observing networks (https://arcticobservingviewer.org/); Arctic Research Mapping Application (https://armap.org/) and the NSF Arctic Data Center (https://arctic data.io) for locating projects and data supported by US funding agencies; Svalbox (www.svalbox.no), a database for digital outcrop models from Svalbard, the comprehensive PANGAEA database (https://www.pangaea.de), a data publisher for Earth and Environmental sciences; and GeoMapApp (http://www.geomapapp.org/), a map-based application for browsing, visualizing and analyzing a diverse suite of curated global and regional geoscience data sets. While a wealth of data can be located and viewed in these databases and data repositories, the scientific community and geoscience educators may benefit from a collection of geological and geophysical data that can be easily visualized, analyzed and used for a quick assessment of present-day geodynamic setting and further for paleogeographic reconstructions in the circum-Arctic region. Consequently, a group of scientists from four Arctic countries and their collaborators are aiming to consolidate and further develop the Arctic-related common scientific basis and educational programmes under the auspices of the Norwegian Research Council programme INTPART (International Partnerships for Excellent Education, Research and Innovation). The project NOR-R-AM (https://norramarctic.wordpress.com/), established in 2017, focused on assessing the openly available information accumulated at participating institutes. During the first phase of this project, we have gathered and interpreted data in various sub-regions, especially in Svalbard and in Russia. The second phase of the NOR-R-AM project aims to complete and launch the digital Circum-Arctic geodynamics platform. This web-based platform will incorporate geological and geophysical data and models, tomographic and kinematic models and paleogeography and paleoclimate indicators. The digital Circum-Arctic geological repository, to be hosted by our project webpage https://norramarctic.wordpress.com/, assembles the data in openly accessible formats that are compatible with GPlates, GeomapApp and Google Earth. These data are consistently formatted to simplify exchange and completely open to the scientific community.

Pitman pioneered research on seafloor spreading, proposed a scientific backstory to the Great Flood and Noah's Ark, and reveled in spirited discussions of all kinds.

Bathymetry (seafloor depth), is a critical parameter providing the geospatial context for a multitude of marine scientific studies. Since 1997, the International Bathymetric Chart of the Arctic Ocean (IBCAO) has been the authoritative source of bathymetry for the Arctic Ocean. IBCAO has merged its efforts with the Nippon Foundation-GEBCO-Seabed 2030 Project, with the goal of mapping all of the oceans by 2030. Here we present the latest version (IBCAO Ver. 4.0), with more than twice the resolution (200 × 200 m versus 500 × 500 m) and with individual depth soundings constraining three times more area of the Arctic Ocean (∼19.8% versus 6.7%), than the previous IBCAO Ver. 3.0 released in 2012. Modern multibeam bathymetry comprises ∼14.3% in Ver. 4.0 compared to ∼5.4% in Ver. 3.0. Thus, the new IBCAO Ver. 4.0 has substantially more seafloor morphological information that offers new insights into a range of submarine features and processes; for example, the improved portrayal of Greenland fjords better serves predictive modelling of the fate of the Greenland Ice Sheet.

The high Arctic is a remote place, where geoscientific research and teaching require expensive and logistically demanding expeditions to make use of the short field seasons. The absence of vegetation facilitates the use of modern photogrammetric techniques for the cost-effective generation of high-resolution digital outcrop models (DOMs). These georeferenced models can be used in pre-fieldwork activities to help prepare for traditional geological fieldwork, during fieldwork to record observations, and post-fieldwork to conduct quantitative geological analyses. Analyses of DOMs range in scale from mm-cm (e.g., size and spacing of dinosaur footprints), to hundreds of meters (e.g., seismic modeling of outcrops and outcrop-well-seismic correlations) and can advance research objectives. This integration is strengthened if key geoscientific data, like geological and topographical maps, subsurface profiles, borehole data, remote sensing data, geophysical data and DOMs can be integrated through a common database, such as the Svalbox database that we present in this commentary. Svalbox geographically targets the Svalbard archipelago, where fieldwork is challenging due to the harsh polar environment, risk of polar bear encounters and demanding transport to the field area. The University Centre in Svalbard nonetheless relies on utilizing the natural Svalbard environment for its field-based education, and now makes use of Svalbox to make geological fieldwork more efficient and post-fieldwork analyses more quantitative. Experience and usage of such tools in geoscientific education, particularly in the polar regions, is not well documented. Therefore, we share experiences on both developing and optimizing Svalbox, and on student and lecturer usage. Svalbox includes a web-based interface through which DOMs are shared and displayed together with relevant public-domain geoscientific data sets. Svalbox also serves as a platform to share student and teacher experiences on the entire DOM workflow, from acquisition to data distribution. For the Svalbox users questioned by the project group, DOMs were found to provide many benefits, including quantitative analyses, extended field season, appreciation of scale and data sharing that significantly outweigh present-day challenges, such as the need for expensive hardware and lack of easily accessible interpretation software, the latter being surmountable within the near-term.

Logging data are measurements of physical properties of the formation surrounding a borehole, acquired in situ after completion of coring (wireline logging) or during drilling (Logging-While-Drilling, LWD). The range of data (resistivity, gamma radiation, velocity, density, borehole images,…) in any hole depends on the scientific objectives and operational constraints.

Logging data are measurements of physical properties of the formation surrounding a borehole, acquired in situ after completion of coring (wireline logging) or during drilling (Logging-While-Drilling, LWD). The range of data (resistivity, gamma radiation, velocity, density, borehole images,…) in any hole depends on the scientific objectives and operational constraints.

Logging data are measurements of physical properties of the formation surrounding a borehole, acquired in situ after completion of coring (wireline logging) or during drilling (Logging-While-Drilling, LWD). The range of data (resistivity, gamma radiation, velocity, density, borehole images,…) in any hole depends on the scientific objectives and operational constraints.

International Ocean Discovery Program Workshop; Mount Hood, Oregon, 25–27 September 2018

Incremental improvements to the Arctic Gravity Project (AGP) grid have accumulated through the steady acquisition of marine gravity anomaly data in the Arctic Ocean and other data sets. The explosion of data collected to establish the Extended Continental Shelves of the Arctic coastal states has increased the available data in and around the Arctic Ocean. A consistent issue with the AGP grid has been a very irregular distribution of gravity anomaly data in Alaska. While parts of the state have been well-surveyed (e.g. the North Slope) much of this remote region has not. Access is difficult. Control points for gravity ties are non-existent. As a result, the anomalous field for Alaska has not been well determined. This may be changing due to the extensive airborne survey conducted by the US National Geodetic Survey. Nearly all of continental Alaska has been flown at similar to 6 km elevation with a 10 km line spacing as a part of the GRAV-D project. These data have been collected by a single group, using consistent procedures and the same equipment. These data form an ideal basis for a new gravity anomaly map for the State of Alaska. Using the new data, collected from ships and the airborne data collected through the GRAV-D project in conjunction with satellite and land data will substantially improve knowledge of the gravity field. All of the new data will be included in the updated AGP grid, which should be available in a year, updating the last release from 2008.

A regional stratigraphic framework is developed for the North Chukchi Basin and southern margin of the Chukchi Borderland based on a grid of 2D multi-channel seismic reflection profiles tied to exploration wells on the U.S. Chukchi Shelf. The northern flank of the North Chukchi Basin displays a 16 km succession of mainly Cretaceous and Cenozoic strata that progressively onlaps an unconformity (Au) on the southern margin of the Borderland. Rocks beneath the unconformity are inferred to represent (A) crystalline basement that may have affinity to the Peary terrane, (B) deformed growth strata that may be related to Carboniferous to Jurassic strata on the Chukchi Shelf, and (C) seaward dipping reflections (SDRs) likely related to oceanic igneous rocks or exhumed mantle beneath the North Chukchi Basin. The SDRs indicate that the southwestern margin of the Borderland is a rifted continental margin and loosely constrained age control suggests that rifting occurred between Middle Jurassic and earliest Cretaceous. Cretaceous through Cenozoic strata that fill the North Chukchi Basin are part of the Brookian megasequence deposited across the foreland of the Chukotka and Brooks Range orogens. These strata form a series of dinothems deposited by northward-migrating depositional systems that progressively filled the North Chukchi Basin and buried the southern flank of the Borderland. Onlap of the Au by bottomset facies indicates that deep water conditions prevailed along the northern basin margin during Aptian-Oligocene. Foreset and topset facies onlap and overtop the highest standing part of the Borderland and indicate that marine slope and shallow marine to deltaic environments reached the Borderland during the Oligocene and persisted thereafter.