Review ArticleEUNAseis: A seismic model for Moho and crustal structure in Europe, Greenland, and the North Atlantic region

- New compilation of seismic data on the crustal Vp structure and new Moho map
- Analysis of intra-crustal and upper mantle seismic parameters
- Ratio between thickness of upper and lower crust as indicator for tectonic origin
- Anomalous oceanic crust of North Atlantics north of 55 N
- Disparity between seismic parameters for the European crust and global averages

We present a new digital crustal model for Moho depth and crustal structure in Europe, Greenland, Iceland, Svalbard, European Arctic shelf, and the North Atlantic Ocean (72W-62E, 30N-84N). Our compilation is based on digitization of original seismic profiles and Receiver Functions from ca. 650 publications which provides a dense regional data coverage. Exclusion of non-seismic data allows application of the database to potential field modeling. EUNAseis model includes Vp velocity and thickness of five crustal layers, including the sedimentary cover, and Pn velocity. For each parameter we discuss uncertainties associated with theoretical limitations, regional data quality, and interpolation.By analyzing regional trends in crustal structure and links to tectonic evolution illustrated by a new tectonic map, we conclude that: (1) Each tectonic setting shows significant variation in depth to Moho and crustal structure, essentially controlled by the age of latest tectono-thermal processes; (2) Published global averages of crustal parameters are outside of observed ranges for any tectonic setting in Europe; (3) Variation of Vp with depth in the sedimentary cover does not follow commonly accepted trends; (4) The thickness ratio between upper-middle (Vp < 6.8 km/s) and lower (Vp > 6.8 km/s) crystalline crust is indicative of crustal origin: oceanic, transitional, platform, or extended crust; (5) Continental rifting generally thins the upper-middle crust significantly without changing Vp. Lower crust experiences less thinning, also without changing Vp, suggesting a complex interplay of magmatic underplating, gabbro-eclogite phase transition and delamination; (6) Crustal structure of the Barents Sea shelf differs from rifted continental crust; and (7) Most of the North Atlantic Ocean north of 55°N has anomalously shallow bathymetry and anomalously thick oceanic crust. A belt of exceptionally thick crust (ca. 30 km) of probable oceanic origin on both sides of southern Greenland includes the Greenland-Iceland-Faeroe Ridge in the east and a similar “Baffin Ridge” feature in the west.