engleski

Quaternary geohazards in External Dinarides - a cautionary tale

In Karst Dinarides we see ample evidence of numerous hazardous events that definitively shook our world. Some of these have been recognized as such, but many remain unrecognized, such as genesis of collapse dolines (sinkholes). Some excellent examples of these karst features are located on the southern Velebit Mt.. A variety of features may have been formed as a consequence of severe seismic shaking, but aseismic generation of rockfalls and collapse dolines may also generate seismic shocks per se. So, it is not always clear what was the trigger of a mass collapse and what was the consequence, particularly in prehistoric times. The paper presents a brief overview of geohazards which have occurred sometime in Quaternary, in the area of Northern Adriatic coast and Velebit Mt. and their products, such as: karst collapses, seismically fractured speleothems, rockfalls, tsunamis, volcanic tephra, and impact ejecta. Geohazards follow a simple rule - they will occur again, it is just unknown - when. The presented geohazards and their products may be grouped in two categories ; a) hazards which may have been triggered by strong earthquakes: collapses of karst underground caverns (formation of collapse dolinas), breakage of speleothems, large rockfalls in large area, tsunamis (rockfall tsunamis) b) hazards which may have occurred “spontaneously”: rockfalls (individual), collapses of karst underground caverns (may be also aseismic), asteroid impacts Several features in External Dinarides may indicate strong paleo-earthquakes: simultaneous rockfalls in larger area, rockfall tsunamis, collapses of karst underground caverns (formation of collapse dolinas), breakage of speleothems. The presented case studies and the geohazard list are not comprehensive, and conclusions are still preliminary since the research is still in progress. It nevertheless indicate the direction of future research for the benefit of providing better understanding of hazardous geological processes.

geohazards, karst collapses, tsunamis, earthquakes

nije evidentirano