GORHAM, Maine—Supersonic shockwaves shook the bones of Charlie Hamblen’s historic Maine farmhouse more than a dozen times last year, travelling over half a mile from blasts at a nearby quarry.
The quarry is one of two active in Gorham, a vibrant and growing town of nearly 20,000 residents a few miles west of Portland, and its frequent blasts are emblematic of a broader trend spanning Maine in recent years: The state’s construction aggregate industry is booming, thanks at least in part to climate change, as property owners erect or repair stone walls to protect against sea level rise, flooding and erosion.
The number of permits to develop new quarries have more than tripled in Maine over the past five years compared to the prior decade, according to the Maine Department of Environmental Protection (DEP). Meanwhile, quarry owners in Gorham and beyond are looking to expand their existing pits, potentially bringing more Maine residents into the pathway of the quarries’ shockwaves.
The 1978 event, what was previously a once in several decade event is now much more frequent. The next highest events prior to 1980, in 1944 and 1947, are now regularly exceeded. The projection for the future is worse.
The US Navy is taking steps to address rising sea levels at its bases. There is also discussion about moving some inland (to what is currently dry land, but won’t be in coming decades) by 2100.
Right, but you wrote that “Flooding events also involve the rise of sea level”. It seems unlikely that an inch or two would make much of a difference in the flooding – which, as you noted, involves many feet (some two order of magnitude greater than the SLR).
I suspect this is a case where the writer threw in sea level change because it is au courant.
Depending on the terrain, a 1.5” rise in sea levels would mean up to a 15 foot loss of shoreline (at 1% slope, less as the slope increases. Most shorelines are between 1% and 10%). So the water is naturally standing further inland.
On top of that waves carry another 5% to 10% of energy higher inland and because the power of a wave increases with the square of the height, waves which used to naturally dissipate farther out will carry more energy to the shoreline - or to dock footings or ships or whatever is in their way.
This “square” rule becomes incredibly important with more dramatic weather events, even just some “typical” storms, not to mention actually “severe” storms like gales, hurricanes, or squalls. Things built to withstand the ravages of the weather in one era may not stand up so well to those which come later.
Based on historical comparisons the us Geological Survey indicates that storms along coastlines are intensifying faster, becoming more frequent, and becoming harsher - all with the expected results. This is driven, it is theorized, by changing weather patterns caused by climate change, differences in thermal layers and the meandering of oceanic thermal zones.
In summary: More storms. More energy. More waves. Ending higher on coastlines. Perhaps none of these alone would’ve a big deal, but the cumulative effect is enough to be seen/felt already, and the trend is not encouraging.
I hope this helps. There have been several articles recently in the popular press everything from the NYT to WSJ about the phenomenon. It’s real. It looks not to be just a statistical blip.
