Seven weeks later , a second earthquake struck offshore Tolaga Bay on 17 May .
Seven weeks later , a second earthquake was estimated to have been between 6.9 -- 7.1 M. It also generated a tsunami , with a maximum measured run up height of 6 metres .
Seven weeks later , a second earthquake struck offshore Tolaga Bay on 17 May , and was estimated to have been between 6.9 -- 7.1 M. It also generated a tsunami , with a maximum measured run up height of 6 metres .