Journalists examined crew lists of more than 2,000 vessels that have been sanctioned by the United States and the European Union, as well as those included on the list maintained by Ukraine's Main Intelligence Directorate.
Following an underwater volcano eruption on Saturday, Tonga has suffered significant damage and is blanketed in ash that closed runways and threatens water supplies.
Evidence from underwater landslides during New Zealand's 2016 Kaikōura earthquake could help scientists better understand the world's largest, tsunami-generating quakes.
