Spatio-Temporal Mapping on the Distribution of Volcanic Products as Construction Materials Using ASTER Images at Southeastern Part of East Java (Indonesia)

The southeastern region of East Java, Indonesia, named Jember Regency, is known as the city of “a thousand volcanic products dune”. Volcanic product, which is generally a dune containing construction materials (sand as a matrix and stone as a fragment), has been widely mined by the local communities as a building material and a foundation for road construction. This study aims to map the distribution of volcanic products from 2016 to 2019 using Aster satellite imagery to analyze their spatiotemporal changes. So that within about three years, the change of construction materials distribution due to the mining activities by local communities can be analyzed. There are two volcanoes in the northwestern and eastern parts of the study area, known as Mt. Argopuro and Mt. Raung, respectively. The field survey results indicated that a few numbers of the product originated from lava flows characterized by columnar joints of andesite and the presence of tuff or lapilli (product of volcanic ash), which is utilized for the concrete brick material by the local community. However, the volcanic product was mainly found as lapilli with some volcanic bomb mixed. A petrographic observation was used to identify the mineral composition and texture and verify the rock types. This study gave a new idea to quickly map hundreds to thousand of volcanic products and report the change in their volume as construction materials.