GEUS is responsible for monitoring and recording earthquakes and other seismic activity in Denmark and Greenland and provides the seismic service. The seismic service collects and archives information about earthquakes that have been felt in Denmark and Greenland, and provides assistance to public authorities and others. on matters relating to earthquakes and nuclear tests.

Data from the Danish and Greenlandic seismographs are used to locate both local and teleseismic earthquakes. In the daily work, data from seismographs in neighboring countries is also used, just as it uses data from the Danish and Greenlandic seismographs. Thereby, GEUS contributes in an international context to more precise localizations of earthquakes and nuclear tests, as well as to closer studies of the processes behind them.

Myndighedsrådgivning inden for seismologi spænder fra hazard- og risikorådgivning til rådgivning om FN-traktaten Comprehensive Nuclear Test Ban Treaty (CTBT), som Danmark tiltrådte i 1996. Rystelser fra atomprøvesprængninger registreres af de danske og grønlandske seismografer og analyseres af GEUS. GEUS repræsenterer Danmark i en teknisk arbejdsgruppe under CTBT, og GEUS er endvidere Danmarks 'National Authority' og 'National Data Center (NDC)' på traktaten i tæt samarbejde med Udenrigsministeriet.