Mantoloking Bridge, Northern New Jersey, March 18, 2007
Mantoloking Bridge after Superstorm Sandy, October 31, 2012
Superstorm Sandy wreaked havoc on the East Coast last week. Camera crews and smartphone-toting locals chronicled the storm’s devastation on the street. These aerial photos, taken 7,500 feet above the ground, demonstrate the destruction on a larger scale. Just north of the spot where Sandy came ashore, the Mantoloking Bridge used to connect this barrier island to mainland New Jersey. The bridge was only two years old when the first picture was taken, in March 2007, but since the storm has washed away much of this former island, it has become, quite literally, a bridge to nowhere.
Images courtesy of the NOAA Remote Sensing Division, NASA.
In this graphic from the restoration authority, the land that will
be lost to erosion if the plan isn’t undertaken is shown in red.
Six years after Hurricane Katrina devastated New Orleans and the Louisiana coast, the state’s Coastal Protection and Restoration Authority has finally released a draft of a plan to try to keep it from happening again. How? By restoring the wetlands along the Mississippi River Delta, which we have more or less systematically destroyed but used to act as buffers between storm surge waves and inland cities.
Previous plans had relied on mainly on building levees and seawalls, so it’s striking that this plan, which would unroll over the course of 50 years at a cost of $50 billion, focuses on wetland restoration, writes Mark Fischetti, who has been covering this issue for Scientific American for years. Here’s how it would work:
Along the outer edge of the torn-up coast, furthest from New Orleans, former barrier islands that have been worn to thin wisps of land would be broadened with sandy sediment, mostly dredged from the ocean bottom and conveyed through pipelines. Natural ridges of land along the coast would be strengthened in similar fashion. Together, the islands and ridges would form a dotted line around southeastern Louisiana that can cut down storm surges. They would not all connect, so wind-driven water could still find its way through, but the many segments would break up the incoming wavefront into chaotic eddies flowing in conflicting directions that would at least partially cancel out one another.
The plan is already drawing ire from fishermen, who say that current restoration projects haven’t had much effect, and that all this shuttling of sand and water will interfere with their livelihoods.
Read more at Scientific American.
Images courtesy of the Coastal Protection and Restoration Authority
The glaciers that form atop mountains can act like a saw or sandpaper, wearing away material as they slide and preventing the peaks from ascending too high. Until now, that’s been the consensus notion of how glaciers shape mountains. But whatever your tool shop metaphor of choice might be, neither saws nor sanders work if the glaciers don’t move. That might explain what’s happening in the far reaches of southern South America, where, scientists led by Stuart Thomson report in Nature, glaciers are not wearing down the Andes Mountains but are actually protecting them from erosion.
In the more temperate part of the range, from 38˚ to 49˚ south latitude, the glacial grinder has shaved off as much as 1000 meters from the mountains’ peaks, flattened their slopes, and smoothed their surfaces. But farther south, between 49˚ and 56˚ latitude, the mountains have been spared: The peaks are higher—some nearly 4000 meters—and the ridges are much more rugged. [ScienceNOW]