Issaouane Erg confined to basins. Sand in the Issaouane Erg, below the level of the sand dunes, has accumulated to a depth of 20 to 30 meters. It has barchan dunes as well as star dunes of 300 to 430 meters high. The presence of both barchan dunes (which form due to unidirectional winds) and star dunes (which form when winds from various directions deposit sand) "suggests that wind regimes have changed over time". NASA's "Earth Observatory" notes all three types of erg dunes are present in the photos of the Issaouane Erg taken from the International Space Station: stationary mega dunes,
Erg (tug) Halifax Harbour and is the greatest loss of life in regards to a shipwreck within these waters. Upon inspection, it was decided that "Erg" was beyond repair and on August 24, 1943, she was taken to her final resting place and sunk for the third and final time. The "Erg" shipwreck site was rediscovered in 2001 in the northern part of the Bedford Basin (near Roach Cove) by the Nova Scotia Exploration Society. The site is a protected heritage site and is visited by many divers. Objects which were recovered from "Erg", such as the ships' whistle and portholes are