Examining Three-Dimensional Crustal Heterogeneity in Finland



The marriage of several high-quality seismic experiments in Finland over the past 30 years has shown that the saying “something old, something new, something borrowed” can result in the cost-efficient analysis of large-scale, three-dimensional (3-D) seismic structures. Standing alone, each data set gives a partial view of complex 3-D structures. When combined, they reveal a 3-D block structure embedded in a layered crust and enable the analysis of dynamics involved in forming stable cratonic crust.

Efforts to collect large 3-D data sets around the globe include EarthScope (funded by the U.S. National Science Foundation (NSF)), the European Science Foundations (ESF) 4-D Topography Evolution in Europe: Uplift, Subsidence and Sea Level Change (TOPO-EUROPE), and the European Space Agency's Gravity Field and Steady-State Ocean Circulation Explorer (GOCE). Such endeavors are fundamental to modern crustal research. Huge emphasis is placed on collecting and archiving these data, but often only a fraction of data are used in initial studies. Fortunately, new data sets can be complemented with vintage ones (e.g., the NSF-funded Consortium for Continental Reflection Profiling (COCORP) and ESFs European GeoTraverse (EGT), as well as continent-wide science programs on continental evolution in Canada (LITHOPROBE), Europe (ESF-funded EUROPROBE), and the Himalayas (NSF-funded International Deep Profiling of Tibet and the Himalaya (INDEPTH)). Because fieldwork and archiving have already been completed for these vintage projects, new information can be extracted by new methods, with considerably less effort and funding.