Map from the study.
(a) Current tectonic map of the Aegean showing active faults (blue) and main structural units (white), and coastlines (black) on the base of Ganas et al. [2013]. (b) Scheme of the evolution of the Aegean over 45 Mio years. First phase (45-15 million years ago (Ma)) shows extension with normal fault (red) development as a consequence of trench retreat. In the second phase (15 Ma-today) higher rates of trench retreat leads to reactivation of the normal faults (red and orange) and generation of new strike-slip faults (red lines). VSZ means Vardar Suture Zones. Credit: Liu et al. [2025], Figure 10
Editors’ Highlights are summaries of recent papers by AGU’s journal editors.
Source: Journal of Geophysical Research: Solid Earth

Continental extension often unfolds in multiple deformation phases, where earlier faults steer the geometry and behavior of later ones. In a new study, Liu et al. [2025] explore the complexity of fault interaction by analogue modeling. 

The models reveal how shifts in stress—from biaxial to triaxial and back—govern the evolution of the fault network. In the triaxial phase, faults from the earlier biaxial phase are reactivated and new conjugate faults appear. When stress shifts back to biaxial, older faults may become inactive or partly reactivated. Stress conditions determine whether old faults block or guide the growth of new ones. Their modeling results are applied to explain the patterns of abandoned, reactivated and newly developed faults seen in the Aegean and Barents Seas. In general, their findings help to shed light on both the tectonic history of their study areas and the distribution of earthquakes.

Citaiton: Liu, J., Rosenau, M., Kosari, E., Brune, S., Zwaan, F., & Oncken, O. (2025). The evolution of fault networks during multiphase triaxial and biaxial strain: An analogue modeling approach. Journal of Geophysical Research: Solid Earth, 130, e2025JB031180. https://doi.org/10.1029/2025JB031180

—Birgit Müller, Associate Editor, JGR: Solid Earth

Text © 2025. The authors. CC BY-NC-ND 3.0
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