A brush fire burns several farms in this image of western Iceland acquired on March 30, 2004. According to various news reports, the fires began when dry grasses ignited – the cause of which is currently unknown. The fire had consumed at least 50 square kilometers (19 square miles) and at least twelve farms at that time. Iceland is often called the “land of fire and ice”; however, generally the fire part refers to its high level of volcanic activity, not the frequency or intensity of its “wild” or “wildland” fires. This is due to the fact that Iceland sits atop the Mid-Atlantic ridge, where two tectonic plates (the American and African) are spreading apart at the rate of 2.54 centimeters (about an inch) per year. Over one-third of the island is active volcano or its direct impacts, such as lava fields. The island is also rife with hot springs; groundwater is heated by subterranean magma and percolates to the surface as steam, where it cools and pools at the surface. Ice, mostly in the form of glaciers, covers about 10% of the land surface currently. However, in the past, ice covered the entire island, and would do so again but for the heat from below.