#OnThisDay 20 years ago, a magnitude 9.1 #earthquake triggered a #tsunami that devastated the Indian Ocean region. Approximately 230,000 people were killed or went missing. Understanding how tsunamis🌊 work can help protect lives and communities: https://t.co/bXq2x1MBol NOAA Satellites Climate Change Science on Telegram by @ClimateChangeScience A @grttme project - Other backups: @Hallotme