Preliminary evaluation of chemical component in the 2004 indian ocean giant tsunami impacted soil using a Co2 Laser Induced Breakdown Spectroscopy (LIBS)

Abstract

Preliminary evaluation of chemical component in soil impacted by 2004 Indian Ocean giant tsunami using LIBS has been carried out. The sampling of the tsunami impacted soil was carried out in several points in Aceh, Indonesia. In this study, the sample soil was pretreated to turn into pellets. The beam of a TEA CO2 laser (10.6 µm, 3 J, 200 ns, 10 Hz) is sent onto surface of pellet using focusing lens under air at atmospheric pressure for producing a plasma. The emission spectral lines from plasma that generated were discovered when testing with Optical Multichannel Analyzer (OMA) system. It shows many emission lines because of various elements could clearly be detected and be identified. It was found that both the tsunami impacted and unimpacted soil sample contain chemical signatures of tsunami event such as saltwater signal (Na), carbonate markers (Ca, Mg, Sr), terestrial markers (Fe, Mn, Si Ti, Ba), and other heavy metal elements. However, it is found that emission intensities of the spectral lines are far higher for the tsunami impacted soil samples compared to the case of tsunami unimpacted soil. The qualitative observation finding implies that the chemical elements such as calcium (Ca), then followed by magnesium (Mg), and sodium (Na) are good candidate for chemical proxies of tsunami event. Since the measurement allows to simultaneously observe these elements in a single measurement, thus LIBS is a potential, simultaneous, efficient, and versatile spectroscopic technique not only for analyzing chemical component in soil affected by the tsunami but also to identify the tsunami impacted soil from the impacted soilThe first section in your paper.