Moho and basement depth in the NE Atlantic Ocean based on seismic refraction data and receiver functions

Thomas Funck,Ögmundur Erlendsson,Uni K. Petersen,Wolfram H. Geissler,Geoffrey S. Kimbell,Sofie Gradmann,Kenneth McDermott

doi:10.1144/sp447.1

Abstract

AbstractSeismic refraction data and results from receiver functions were used to compile the depth to the basement and Moho in the NE Atlantic Ocean. For interpolation between the unevenly spaced data points, the kriging technique was used. Free-air gravity data were used as constraints in the kriging process for the basement. That way, structures with little or no seismic coverage are still presented on the basement map, in particular the basins off East Greenland. The rift basins off NW Europe are mapped as a continuous zone with basement depths of between 5 and 15 km. Maximum basement depths off NE Greenland are 8 km, but these are probably underestimated. Plate reconstructions for Chron C24 (c. 54 Ma) suggest that the poorly known Ammassalik Basin off SE Greenland may correlate with the northern termination of the Hatton Basin at the conjugate margin. The most prominent feature on the Moho map is the Greenland–Iceland–Faroe Ridge, with Moho depths >28 km. Crustal thickness is compiled from the Moho and basement depths. The oceanic crust displays an increased thickness close to the volcanic margins affected by the Iceland plume.

Highlights

Have shaped the present configuration of the crust in the NE Atlantic realm
The basement, Moho and crustal thickness maps compiled from the seismic data are shown in Figures 3, 6 and 7, respectively
A brief description of the main observations is given while some features of the maps are discussed in more detail

Summary

Introduction

Have shaped the present configuration of the crust in the NE Atlantic realm. The first-order structure of the crust can be recognized by regional mapping of the Moho and basement depth. Large parts of the region are included in compilations that cover the European plate (Grad et al 2009; Molinari & Morelli 2011) In contrast to these existing maps for the NE Atlantic Ocean, the new compilation is exclusively compiled from seismic refraction data supplemented by receiver functions along the bordering land areas. To allow for the best possible quality control and internal consistency, existing local compilations were not incorporated into our database Examples of such compilations are the seismically constrained gravity inversion for Iceland (Kaban et al 2002) or the model for the Barents Sea (Ritzmann et al 2007) that is based on both seismic reflection and refraction data, as well as on gravity modelling. AWI 97260 and Barents 98 line 9 ARK 1988 lines 3 – 6 DLC 94 line 5 EAGER 2011 lines 1 – 3 GEUS 2002 lines A and B LOS 2004 lines A and B SIGMA lines 1 – 4

Results

Discussion

Conclusion