Flag of Guam
The flag of the United States territory of Guam was adopted on February 9, 1948. The territorial flag is dark blue with a narrow red border on all sides (border was a later addition). Narrow red border represents the blood that it ravaged in World War 2 and Spanish sovereignty. In the center of the flag is the coat of arms; an almond shaped emblem, which depicts a proa sailing in Agana Bay near Hagåtña, and "GUAM" colored in red letters. The shape of the emblem recalls the slingshot stones used by the islanders' ancestors. The landform at the back depicts the Punta Dos Amantes cliff on Guam. Charles Alan Pownall approved the flag's shape in 1948.
Guam
The Mariana chain of which Guam is a part was created by collision of the Pacific and Philippine Sea tectonic plates. Guam is the closest land mass to the Mariana Trench, the deep subduction zone that runs east of the Marianas. Due to its location on the Mariana Plate just westward of where the Pacific Plate subducts the Mariana and the Philippine Sea Plates, Guam occasionally experiences earthquakes. In recent years, most with epicenters near Guam have had magnitudes ranging from 5.0 to 8.7. Unlike Anatahan in the Northern Mariana Islands, Guam is not volcanically active, though vog (volcanic smog) from Anathan affects it due to proximity.