New preliminary insights into the Dalvik Lineament in North Iceland, earthquakes, landslides, dikes, and geothermal resources

In the past century, seismicity in Tröllaskagi, North Iceland, has resulted in infrastructure damage and landscape changes. However, the faults responsible for these events (up to M_w 6.3) and the persistent trend of microseismicity in the region, the Dalvik Lineament (DL), are poorly understood. Drone surveys, fieldwork, and remote sensing methods were used to map faults, dikes, and Quaternary elements such as large landslides along the DL. Preliminary results include the observation that landslide distribution and frequency correlate with seismicity along the DL and that dikes found in the field share the same orientation as trends present in the microseismicity data in locations with high concentrations of landslides. Microseismicity trends and dikes are oriented north-south in Tröllaskagi, and many of the landslides have headscarps coincident with dikes. While prior studies suggest that landslide events were triggered by glacial debuttressing, our data suggest additional seismic and structural controls on failure in the Tröllaskagi region. These landslides also provide insight into the location of sometimes concealed yet active faults, where abundant moss cover and geomorphological processes (i.e., slope creep) obscure neotectonic features. Finally, low-temperature geothermal fields in Tröllaskagi align with the dikes, emphasizing the importance of geological structures in controlling subsurface fluid flow.