Post tsunami changes in soil properties of Andaman Islands, India

Abstract

A post tsunami study was conducted to assess the changes in soil properties in the Andaman Island, in India. The present study reported tsunami led conversion of acid soils to saline acid soils and acid sodic soils to acid saline sodic soils in the areas South Andaman inundated during tsunami and permanently receded later and in the low-lying area submerged during high tides. Upon intense leaching acid saline soils and acid saline sodic may further develop typical characteristics of acidic soils and acidic sodic soil, respectively. The soil at Guptapara inundated almost due to tsunami with minimal pyrite oxidation has potential to develop into highly acidic soils upon drainage. The tsunami by and large has modified some depositional layer affecting the salt accumulation to a greater extent and iron to a lesser extent and least to sodicity.

Environmental DNA signatures distinguish between tsunami and storm deposition in overwash sand

“…Our observation is in agreement with the studies summarized in Table 1 that microbial communities were different between tsunami deposited sediments and non-tsunami soils and sediments. Similar to Nayak et al 25 , Asano et al 28 , Godson et al 26 , and Somboonna et al 29 , we observed that tsunami deposits have relatively lower diversity as compared to nontsunami soils and sediments (Fig. 3).…”

“…There is a considerable amount of literature describing how microbial communities in different environmental settings respond to abrupt and intense "pulse" disturbances (i.e. relatively short-duration and discrete environmental alterations) 23 due to catastrophic events such as coastal flooding 21,[24][25][26][27][28][29] , wildfire 30,31 , earthquake 32,33 . The primary aim of such studies is commonly to investigate how microbes respond to a disturbance in nutrients 21,[28][29][30] , water resources 24,25 , substrate availability 25,[27][28][29][30][31][32] , or other physical environment changes 23,[31][32][33] .…”

“…To date, several studies have focused on microbial community changes after a tsunami flooding event (Table 1). A number of studies utilize conventional culturing techniques that target the culturable fraction of the microbial communities [24][25][26][27] . However, the culturable fraction of the community is unlikely to contain a detailed signature of the type of overwash since only a few microorganisms (<5%) within natural microbial communities are culturable 34,35 .…”

Applications of geochemistry in tsunami research: A review

“…Nayak et al (2010) measured exchangeable Al and analysed iron fractionation. They concluded that the tsunami caused the conversion of acid soils to saline acid soils and sodic soils to acid saline sodic soils, and that the tsunami not only caused soil salinity but also affected Fe mobility Ilayaraja et al (2012).…”