Although Indonesia experiences very large, great, and giant thrust earthquakes offshore at the Sunda Trench, this was a large strike-slip event that occurred on the southern coast of Java near the city of Yogyakarta. Mount Merapi lies nearby, and during its many previous historical eruptions, large volume lahars and volcanic debris flowed down its slopes where settlements were later built. This unconsolidated material from the stratovolcano amplified the intensity of the shaking and created the conditions for soil liquefaction to occur. Inadequate construction techniques and poor quality materials contributed to major failures with unreinforced masonry buildings, the most prevalent type of home construction, though other styles fared better.