Fire Shadows
Pinelandpaddler, my good friend,
I’m not an expert at forest fire behavior, but this is how I understand the process. Fire shadows are associated with wildfires. The theory is that catastrophic forest fires create visibly distinct spatial patterns since some areas will burn hotter than others leaving an elongated patchwork of hot and cold burned vegetation. Firestorms are known to create their own winds with updrafts and vortices. Anyone who’s been through real Pinelands wildfires can attest to their ferocity. A similar effect is known from hurricanes, where houses are mowed down on one block, but remain unharmed on the next.
In the Pinelands, dunes and other windblown landforms are often confused with fire shadows when viewed on aerial photos. The Newtonville dunefield is a good example (see Pinelands Watch SE-11 [Special Edition] and New Jersey Audubon Fall/Winter 2007-2008 [Special Places Issue]: 32-33). Eolian features were created throughout the Pleistocene, when strong katabatic winds blew off a massive ice sheet that parked itself on multiple occasions just north of the Raritan River. Don’t expect to see huge dramatic dunes, since South Jersey was sand-starved when desert-like. Currents of air were so strong that deflation and not deposition predominated, and the ground was frozen when winds were strongest.
I have a geologic talk scheduled for 7:00 PM, Friday, April 17 at the new Jakes Branch County Park. Some of eolian stuff will be covered, along with a mix of cultural and environmental material. Don’t worry; strong coffee will be in ample supply!
