Around 30 million tonnes of ice fell off Tasman Glacier into Tasman Lake , about 200 k from the epicentre , hitting tour boats with waves 3.5 high . At the Tasman Glacier some 200 k from the epicentre , around 30 million tonnes ( 33 ST ) of ice tumbled off the glacier into Tasman Lake , hitting tour boats with tsunami waves 3.5 m high .