Editing Tsunami (section)

=== Human-made or triggered tsunamis ===
{{see also|Tsunami bomb}}

The accidental [[Halifax Explosion]] in 1917 triggered an {{convert|18|metre|adj=on}} high tsunami in the harbour at [[Halifax, Nova Scotia]], Canada.<ref>{{Cite book|last=Mac Donald|first=Laura|title=Curse of the Narrows: The Halifax Explosion of 1917|publisher=HarperCollins|year=2005|isbn=978-0-00-200787-0|page=66|url=https://archive.org/details/curseofnarrowsth00macd}}</ref><ref>{{cite book|last1=Krehl|first1=Peter|title=History of shock waves, explosions and impact a chronological and biographical reference|date=2007|publisher=Springer|isbn=978-3-540-30421-0|page=459}}</ref>

There have been studies of the potential for the use of explosives to induce tsunamis as a [[tectonic weapon]]. As early as [[World War II]] (1939–1945), consideration of the use of conventional explosives was explored, and [[New Zealand Defence Force|New Zealand's military forces]] initiated [[Project Seal]], which attempted to create small tsunamis with explosives in the area of what is now [[Shakespear Regional Park]] at the tip of the [[Whangaparāoa Peninsula]] in the [[Auckland Region]] of [[New Zealand]]; the attempt failed.<ref name="PART2-P9">{{cite news|title=The Hauraki Gulf Marine Park, Part 2|date=3 March 2010|work=Inset to [[The New Zealand Herald]]|page=9}}</ref>

There has been considerable speculation about the possibility of using [[nuclear weapon]]s to cause tsunamis near an enemy coastline.  Nuclear testing in the [[Pacific Proving Ground]] by the United States generated poor results. In [[Operation Crossroads]] in July 1946, two {{convert|20|ktTNT|abbr=on|adj=on}} bombs were detonated, one in the air over and one underwater within the shallow waters of the {{convert|50|m|0|adj=on}} deep [[lagoon]] at [[Bikini Atoll]]. The bombs detonated about {{convert|6|km|mi nmi|abbr=on}} from the nearest island, where the waves were no higher than {{convert|3|to|4|m|abbr=on}} when they reached the shoreline. Other underwater tests, mainly [[Operation Hardtack I]]/Wahoo in deep water and Operation Hardtack I/Umbrella in shallow water, confirmed the results. Analysis of the effects of [[underwater explosion#shallow underwater explosions|shallow]] and [[underwater explosion#deep underwater explosions|deep]] underwater explosions indicate that the energy of the explosions does not easily generate the kind of deep, all-ocean waveforms typical of tsunamis because most of the energy creates [[steam]], causes vertical fountains above the water, and creates compressional waveforms.<ref>{{cite book|last1=Glasstone|first1=Samuel|author-link1=Samuel Glasstone|last2=Dolan|first2=Philip J.|date=1977|title=Shock effects of surface and subsurface bursts (in ''The effects of nuclear weapons'')|edition=third|publisher=U.S. Department of Defense; Energy Research and Development Administration|url=https://www.atomicarchive.com/resources/documents/effects/glasstone-dolan/chapter6.html}}</ref> Tsunamis are hallmarked by permanent large vertical displacements of very large volumes of water which do not occur in explosions.