- 1Kyoto University Graduate School of Engineering, Kyoto, Japan (sakai.yuhi.68c@st.kyoto-u.ac.jp)
- 2Kyoto University Graduate School of Engineering, Kyoto, Japan
- 3iC3 – Center for ice, Cryosphere, Carbon and Climate, Department of Geosciences, UiT The Arctic University of Norway, Tromsø, Norway.
- 4National Institute of Oceanography and Applied Geophysics - OGS, Trieste, Italy
- 5James Madison University, Harrisonburg, USA
- 6Texas A&M University, International Ocean Drilling Program, College Station, USA
- *A full list of authors appears at the end of the abstract
The Eastern Fram Strait is of high geo-mechanical interest for studying how regional forcing has influenced the continental margin’s hydrology, having an impact on slope stability and climate evolution. The region is subjected to tectonic stress fields induced by a cluster of mid-ocean ridges and transform faults as well as to glacial stresses associated with the evolution of the Svalbard-Barents Sea Ice Sheet. Studies over the last decade show that seafloor methane seepage is impacted by the spatiotemporal evolution of the aforementioned stress factors. However, in-situ stress measurements from the area have been lacking to constrain stress regime inferences from geophysical data and stress models.
During International Ocean Discovery Program (IODP) Expedition 403, borehole resistivity images were obtained in Holes U1618B within the second northernmost site and U1623D within the southernmost site in the expedition using Fomation-MicroScanner (FMS). The maximum and minimum principal horizontal stress orientations can be inferred from those borehole resistivity images that indicate failures of borehole walls subsequently caused after drilling. After processing and observation in combination with caliper logs, borehole breakouts and/or drilling induced tensile fractures were recognized in both boreholes. For U1618B (located on the Vestnesa ridge, an active seafloor seepage system), very scarce borehole compressive failures were recognized possibly due to weak horizontal compression implying normal stress regime. For U1623D (located offshore the Bellsund fjord), there were multiple borehole failures with large fluctuations of azimuth implying presence of local stress or small differential stress. Our results would provide the first actual data to discuss stress fields in the Eastern Fram Strait in combination with existing model-based studies contributing the advance of understanding geo-mechanics regarding seafloor fluid dynamics.
Yair Rosenthal, Jens Grützner, Olga Libman-Roshal, Lindsey Monito, Yusuke Suganuma, Catalina Gebhardt, Adriane Lam, Sijin K. A. Veedu, Gryphen Goss, Nicole Greco, Isuri U. Kapuge, Brendan Reilly, Yi Zhong, Katrine Husum, M. Angeles Barcena, Stijn De Schepper, Alba González-Lanchas, Yanguang Liu, Mutsumi Iizuka, Lucinda Duxbury, Lauren Haygood, and the JOIDES Resolution Expedition 403 Technical Support Team
How to cite: Sakai, Y., Lin, W., Plaza-Faverola, A., G. Lucchi, R., St. John, K., and Ronge, T. and the IODP Exp.403 Science Party: Observation of borehole resistivity images from IODP Exp.403 implying stress fields exerted on the sedimentary succession in the Eastern Fram Strait, EGU General Assembly 2025, Vienna, Austria, 27 Apr–2 May 2025, EGU25-14942, https://doi.org/10.5194/egusphere-egu25-14942, 2025.
