Some results from a transversely excited atmospheric carbon dioxide-laser induced breakdown spectroscopy investigation of tsunami deposit cored from Aceh Besar coastal region

Abstract

Abstract We undertook an extensive analysis to examine the geochemical imprints encapsulated within the samples of the 2004 Indian Ocean tsunami deposits procured from the Seungko Mulat coastal region, nestled in the western section of Aceh Besar Regency, Aceh Province, Indonesia. In order to induce the formation of micro-plasma, a Transversely Excited Atmospheric Carbon Dioxide-Laser Induced Breakdown Spectroscopy (TEA CO2-LIBS) has been employed as the excitation source. Our investigation unveils distinct spectral signatures within every layer of the stratified tsunami deposit. We observed the unmistakable presence of salt elements (Ca, K, Mg, Na, Al), transition metals, heavy metals (Si, Fe, Ti, Ba, Sr, Cu, Cr, Pb, Mn, Ni, V), and also organic constituents (C, H, O, and N). The emission intensities of these elements exhibited a significant increase within the layers of the tsunami deposit, unequivocally setting them apart from their non-tsunami equivalents. In addition, we performed a vertical analysis of LIBS elemental emission intensity ratios, unveiling unique values for the Ca/Ti, and Si/Ti, ratios, which significantly distinguish them from all other ratios scrutinized in this exhaustive investigation. This research serves to highlight the effectiveness of TEA-LIBS as a promising and efficient optical technique for discerning the chemical profile associated with the renowned 2004 Indian Ocean tsunami deposits from Seungko Mulat Village in Aceh Province.