Naslov
Magnetic susceptibility of soil from Seget Gornji (South Croatia) under different heating exposure: wildfire vs. laboratory furnace

Autori
Peco, Josip ; Fajković, Hana ; Frančišković-Bilinski, Stanislav

Vrsta, podvrsta i kategorija rada
Sažeci sa skupova, sažetak, znanstveni

Izvornik
17th “Castle Meeting” on Palaeo, Rock and Environmental Magnetism : Book of Abstracts / Frančišković-Bilinski, Stanislav ; Böhnel, Harald ; Egli, Ramon ; Hirt, Ann ; Petrovsky, Eduard ; Spassov, Simo ; Werner, Tomasz - Zagreb : Institut Ruđer Bošković, 2022, 98-98

ISBN
978-953-7941-44-4

Skup
17th Castle Meeting New Trends on Paleo, Rock and Environmental Magnetism

Mjesto i datum
Trakošćan, Hrvatska, 28.08.2022. - 03.09.2022

Vrsta sudjelovanja
Poster

Vrsta recenzije
Međunarodna recenzija

Ključne riječi
wildfire ; Seget Gornji ; magnetic susceptibility ; Fe oxides and hydroxides

Sažetak
Wildfires affect soil characteristics and change mineralogical composition of the soil. Fe oxides and hydroxides are prone to thermal changes during the wildfire resulting in a consequent change in magnetic susceptibility (MS) (e.g. Jordanova et al., 2019). The studied area located in the northern part of the Seget Gornji (Trogir) presents a hill slope of burned low vegetation and maquis. For this study, soil and ash samples were collected from seven different burned sites across the hill. The control soil sample was collected from unburned site about one kilometer of airline distance away western of the burned area. The wildfire occurred in the first few days of August 2021 ; therefore, the sampling was performed two weeks and two months after the wildfire. At the burned sites, soil samples were collected from the 05 cm depth in both sampling times. White and black ash samples were collected from the burned surface only in the first sampling. The sampling of the control soil was conducted at two different depths (05 cm and 2030 cm) for obtaining background values and further heating laboratory experiments for data correlation. The muffle furnace was used to heat both shallow and deep control soil subsamples at 12 temperatures (25, 150, 200, 250, 300, 350, 400, 450, 550, 650, 700, and 1100°C) for two hours. The MS of the samples was determined by a small magnetic susceptibility meter SM-30. Magnetic measurements were performed three times, and the mean value was used as a final result to assure the biggest precision of the data. The overall results of volume‑specific magnetic susceptibility () are in the range of 0.1739.770  10 3 SI. Generally, soil samples from the burned sites show  values from 0.969 to 1.997  10 3 SI. Only for the samples from one burned site, the  value is almost two times higher than all the other values. Furthermore, there is no significant difference in the  values between the results from both sampling times. Shallow (05 cm) and deep (2030 cm) heated control soil subsamples show  results in the range of 0.1739.770  10 3 SI. The MS values for the heated control soil subsamples do not show significant variations in the range of 25 to 550°C. It is important to note that the sudden change of  can be seen between the 550 and 650°C where  values become almost four times higher in both shallow and deep subsamples, with the tendency to rise until 700°C. The last heating temperature of 1100°C, in turn, shows a sharp decrease of  value for both shallow and deep subsamples, which becomes about twelve times lower. Ash samples show  values from 0.876 to 2.917  10 3 SI units. The values of  for the white ash samples are generally higher than the ones for the black ash samples. Further research and determination of mineralogical and thermal changes of Fe oxides and hydroxides will show the main reasons for the differences in the determined  values for the soil and ash samples.

Izvorni jezik
Engleski

Znanstvena područja
Geologija, Geofizika, Interdisciplinarne prirodne znanosti

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