4DARCTIC: Structure and Evolution of Arctic crust and mantle based on multi-scale geophysical studies

Hovedmålet for dette samarbeidet med russiske forskere under 4D Arctic prosjektet er er å utvikle en geodynamisk modell for den Arktiske regionen. Vi vil finne ut hvor gammel og tykk jordeskorpen er I det Arktiske området og hvordan skorpen har blitt endrett av den underliggende mantel. Fo å utføre denne oppgaven broker vi hovedsakelig geophysiske data og platetektoniske metoder. Den nye modellen av nåværende kontinental og osean skorpe i High Arktis - ArcCRUST - inkluderer: skorpe tykkelse, sediment tykkelse, og dybde til Moho diskontinuitet (Lebedeva-Ivanova et al, in review). 4D arktiske studier har blitt publisert i 2016 i fire vitenskapelige artiklerer og 13 konferanse foredrager Prosjekt resultatene blir nå brukt til den strategiske norske konsortiet initiativet "GoNorth - Kunnskaps Bygging i polhavet". Sammen med Universitetet i Oslo International School (ISS) har vi utviklet en tverrfaglig Master kurset: "A Changing Arctic"; der presenterer vi geologi og geofysikk i denne regionen (2/3 av kurset) blandet med lov og statsvitenskap (1 / tredje av kurset). Kurset ble undervist i 5 uker i juni / juli 2014, 2015 og 2016. Det vil bli tilbudt av UiO ISS hvert år.

We aim to undertake an interdisciplinary collaborative project with Russian partners where existent and new geophysical data will be used to build multi-scale models that will unravel the structure and evolution of Arctic's crust and mantle and their inte raction through time. We will assemble, quality-check and compile a variety of geophysical data (potential field, paleomagnetic, heatflow, bathymetry, seismic data, etc) and geological evidences for volcanism and vertical movements through time in order t o be able to characterize the heterogeneities of the present-day Arctic crust and model its kinematic evolution since the Late Jurassic (ca. 150 million years ago). New, multi-scale tomographic models for the Arctic mantle will be constructed using travel time data from the global ISC catalogue. In order to cover the less seismic active areas or with low seismic station coverage, reflected PP data will be also included and to further improve the resolution and reliability of the tomographic models in some regions, we plan to add any available information from regional networks, as well as data on Russian super-long seismic profiles acquired with nuclear explosions. Besides regional models of 1000s km scale, we plan to study the crust and uppermost mantle in selected regions (10s-100s km scale) based on local seismicity data, including data from network deployments on drifting ice. Acquisition of new seismic data along the Russian Arctic coast is also part of this project. Kinematic reconstructions and reg ional tomographic models of the Circum-Arctic regions will be used to construct geodynamic models that will include 3D numerical calculations of the mantle flow using existent academic codes and new software developed by Russian and Norwegian participant s. Finally, we will compute the dynamic topography due to the mantle flow and mantle plumes and assess its implications to anomalous subsidence and volcanism in the Arctic area through time