No matter which camp you side with in the 'Climate Change' discussion, its effects cannot be denied.period. Polar vortexes, massive flooding, snow in deserts, excessive drought, etc... we've all been privy to it the last few years no matter where we are in this world, in the extreme, and whether it happens sooner or later, these changes will continue unchecked. However, without getting into said debate, this blog & episode is about how climate change is not just affecting our atmospheres, oceans, and seas, but as a byproduct- our submerged heritage as well. If you're a maritime archaeologist, a scuba diver, someone fascinated by shipwrecks or just someone interested in the past- this means you should be concerned for all of the knowledge that could potentially be lost because of climate change affecting the preservation and ability to document submerged sites.
|The author diving on a WWII shipwreck in Santorini|
As Katie (The Digger) asks in this episode, how can things like rising sea levels make a difference for a site that is already underwater? Well rising sea levels create two problems- 1. sites that are not yet submerged, but may soon be. Even with the right protection, many of these sites are location specific and whole settlements that cannot be moved - Jamestown V.A.- the site of the first English settlement in America or the Statue of Liberty in NYC, amongst others, are predicted to be underwater within another 100 years! What can be done to prevent this? If people would cut their carbon emissions, it could slow down the rate of these predictions of sea level and temperature rises. 2. For sites already underwater, as discussed in the episode (all other environmental factors aside), a rise in water level on sites significantly reduces the amount of time that divers/maritime archaeologists can spend on the site. This might not seem like as big of a deal, but when you take into consideration how costly an underwater archaeological excavation already is, then if the time spent on a site continues to reduce, a full study could take years longer. English Heritage archaeologist Mark Dunkley describes "the effect of sea level rise on archaeological diving projects will be to incrementally reduce the amount of time (and therefore productivity) an air-breathing diver can spend underwater safely. For example, a 20% increase in diving depth can result in a 32% decrease in dive time." Not to forget that the deeper a site gets, the more expensive high tech equipment will be needed for proper documentation.
|Teredo navalis (shipworm type) in wood|
If you refer to an earlier blog "Forgotten Legacy of WWII Wrecks- Environmental Hazard or Underwater Cultural Heritage?" you'll recall why the scientific world is also concerned because "shipwrecks, ocean acidification and waste dumping into oceans are among the biggest sources of ocean pollution. Some 75% of sunken wrecks date back to the Second World War; their metal structures are therefore ageing and the plates deteriorating, threatening to release their contents into the ocean under the effect of corrosion. The North Atlantic Ocean has 25% of the potentially polluting wrecks in the world, which can contain up to 38% of the total volume of oil trapped in sunken vessels" says the Council of Europe in 2012.