a land continuously carved and molded by vast glaciers but in one fud in the east of Greenland a seismic event has transformed the landscape here forever so we're seeing here sort of a simulation of how this seismic signal traveled around the world when we run this we will start to see this wave this animation shows the signal that baffled scientists for 9 days in September of last year the dots are seismic monitors around the world picking up vibrations from something happening in Greenland at the same time that scientists were puzzling over that a team working in Greenland received a report of a large tsunami in the east of the country these photographs show what caused it a huge Landslide into this fud look at the mountain top in this image taken before the event and look at it afterwards the top of the mountain is gone collapsed into the fud taking parts of the glacier with it the scientists analyzed the depth and shape of this narrow 200 km long F and that revealed why the tsunami the landslide caused reverberated around the world for so long the wave was essentially trapped the energy of that wave just can't escape so that wave has to just keep bouncing back and forth slushing back and forth in the fuel it just can't go anywhere never before was such a long duration sort of move large scale movement of water over nine days in this case been observed remote as it is this is a location that cruise ships doe visit fortunately no vessels were in the area when the landslide happened but scientists say the risk of these events is increasing with climate change this Glacier was holding up the mountain over decades it melted and thinned and eventually millions of cubic meters of rock simply collapsed it's a destructive side effect of climate change that was felt around the world Victoria Gill BBC News