WAVES GENERATED BY LANDSLIDES IN NORWEGIAN FJORDS AND LAKES

WAVES GENERATED BY CALVING OF GLACIERS, SNOW AVALANCHES, DIFFERENT TYPES OF SOIL SLIDES, ROCK FALLS AND ROCK SLIDES INTO FJORDS AND LAKES IN NORWAY ARE DESCRIBED. WAVES RESULTED FROM A SLIDE ENTERING A FJORD OR A LAKE ARE CALLED SLIDE WAVES OR SOMETIMES A FLOOD WAVE. THE SIZE OF THE WAVE AND THE MAGNITUDE OF THE DAMAGE DEPENDS ON THE VOLUME OF SLIDE DEBRIS, DISTANCE OF TRAVEL AND THE VELOCITY WITH THE MASS ENTERS THE WATER, AND THE VOLUME OF THE BODY OF WATER. IN THE CASE OF SNOW AVALANCHES, CLAY SLIDES, FLOW SLIDES AND OTHER TYPES OF SOIL SLIDES, THESE USUALLY CAUSE MODERATE WAVES AND DAMAGE IS RESTRICTED TO NEAR-SHORE STRUCTURES. IN THE CASE OF ROCK SLIDES, THE VOLUME OF MASSES RELEASED FROM THE MOUNTAINSIDE MAY BE OF THE ORDER OF MILLIONS OF CUBIC METERS. THESE WAVES MAY HAVE A CASTASTROPHIC EFFECT ON BUILT-UP AREAS ALONG LAKES OR FJORDS. IN CONSIDERING THE DAMAGE OF ROCK SLIDES AND WAVES POSSIBLY RESULTING, THE VOLUME OF ROCK MASSES RELEASED FROM THE MOUNTAINSIDE MUST BE CONSIDERED. BECAUSE THERE ARE MANY UNKNOWN FACTORS TO BE CONSIDERED IN CONNECTION WITH SLIDE WAVES, THE ONLY METHOD OF DETERMINING THESE IS BY MODEL STUDIES. EXPERIENCE SHOWS THAT SLIDE WAVES GENERALLY REACH THEIR LARGEST HEIGHT DIRECTLY ACROSS FROM THE SLIDE AREA AND THAT THE HEIGHTS DIMINISH RATHER QUICKLY TO THE SIDES.