Tsunami Boulders on the Rocky Coasts of Ibiza and Formentera (Balearic Islands)

Giant tsunami boulders, some weighing up to 43 tons, have been identified along the rocky coasts of Ibiza and Formentera (Balearic Islands), positioned up to 11 meters above sea level and kilometers inland. These boulders, located predominantly in southern coastal areas—contrary to storm wave patterns—correlate with tsunami simulation models predicting northern African submarine earthquake impacts. Radiocarbon dating and dissolution pan growth rates indicate the boulders were deposited between 1750 and 1870 AD, aligning with historical records of a devastating 1756 tsunami that struck the southeastern coast of Majorca. The study suggests these boulders were transported by northern African tsunami waves, supported by their distribution, imbrication direction, and required run-up distances.

Roig-Munar, F. X., Rodríguez-Perea, A., Martín-Prieto, J. A., Gelabert, B., & Vilaplana, J. M. (2019). Tsunami Boulders on the Rocky Coasts of Ibiza and Formentera (Balearic Islands). Journal of Marine Science and Engineering, 7(10), 327. https://doi.org/10.3390/jmse7100327