Study of the tsunami wave run-up using dimensional analysis

Tsunamis are among the most severe natural hazards known to man, and they have claimed thousands of lives and destroyed vast amounts of property throughout history. Several previous researches studied the tsunami wave run-up and its inundation to the coasts and their effect on the coastal communities. In the current study, the Dimensional analysis (DA) method was used for formulating rational hypotheses for the complicated physical conditions connected to the wave run-up study. Pairs of empirical formulas were derived: the first one for the non-dimensional wave run-up over a sandy beach, and the other for the wave run-up over the armoured beach. Based on the obtained experimental results, which were adopted as an input data for the program of IBM SPSS Statistics, v26, both formulas showed a good agreement as the coefficients of correlation were 0.93 and 0.98, respectively.

Potential of Paitan (Tithonia diversifolia) and Cow Manure For Available Nutrients Supply On Sandy Beach Soil

The primary macronutrients are required in large amounts for optimum plant growth. Sandy beach soil that is widely distributed, has a granular structure and is poor in primary macronutrients. Cow manure can improve the struktur of soil and Paitan (Tithonia diversifolia) can increase the availability of primary macro nutrients. This study aims to determine the effect of cow manure and Paitan (Tithonia diversifolia) on the nutrient availability of sand beach soil. The study used a completely randomized design (CRD) with 2 factors, the first factor was the dose of cow manure consisting of 3 levels 0; 2.5 and 5% of the weight of the soil. The second factor is the dose of Paitan (Thitonia diversifolia) which consists of 4 levels of 0; 2.5; 5 and 7.5%. of soil weight To determine the effect of treatment, variance analysis (ANOVA) was used and followed by a follow-up test using Duncan Multiple Range Test (DMRT) at a test level of 5%. The results showed that the application of cow manure and Paitan (Thitonia diversifolia) had a significant effect on increasing N available , P available and K available nutrients. The application of 5% cow manure and Paitan (Thitonia diversifolia) 5% has the potential to increase N available , P available and K available. sand beach soil is the highest

Variety of the drift pumice clasts from the 2021 Fukutoku-Oka-no-Ba eruption, Japan.

Pumice rafts that arrived at the Nansei Islands, Japan, provided a unique opportunity to investigate the Fukutoku-Oka-no-Ba (FOB) eruption of August 2021. Despite drifting for two months for >1300 km, the drift pumice raft had a large volume and contained a variety of pumice clasts, some of which were deposited during a high tide in a typhoon, while others were washed up on a sandy beach. Most of the drift pumice clasts are gray in color, vesicular, and have a groundmass containing black enclaves, which are similar to those collected in the ocean near FOB about one week after the eruption. Rare black pumice and the main gray pumice components have similar trachytic compositions, with SiO2 = 61–62 mass% and total alkalis = 8.6–10 mass% (on an anhydrous basis). Both pumice types contain clinopyroxene, plagioclase, and rare olivine phenocrysts. Thin-section observations show that the gray pumice has more elongated vesicles as compared with the black pumice that has spherical vesicles, even where the two types of pumice are in the same clast. The glass in the black pumice is transparent and brown in color, while that in the gray pumice is colorless. No micro or nano-crystals were observed during electron and optical microscopy in the brown domain. Raman spectra of the brown-colored glass exhibit a clear magnetite peak, suggesting magnetite nanolites cause the brown color. High-Mg (100 × Mg/[Mg+Fe] = 92) olivine in the black pumice has an equilibrium temperature of 1240 °C and a rim diffusion profile indicative of re-equilibration with the surrounding melt over a period of hours to days.The textural relationships between the gray and black pumice suggest that the black pumice had become black and viscous before the two types of pumice mixed. Therefore, crystallization of magnetite nanolites and a corresponding increase in melt viscosity were important in the eruption preparation process, which then resulted in a large-scale Plinian eruption.