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) Erg (tug) Erg was a vessel built and owned by Halifax Steamship Ltd. in 1915. She was used to ferry workers across the harbour to vessels under repair during the Second World War. "Erg" was sunk in the Halifax Harbour three times and is currently located in the Bedford Basin. "Erg" was originally a steam tug called "Sambro" and was built by the Halifax Shipyard in 1915. She was one of the earliest steel vessels to be built in Halifax. "Sambro" was 55 feet long and almost 15 feet wide, with a depth of 7 feet and her maximum tonnage