การสำรวจเหตุการณ์แผ่นดินไหวยุคโบราณบริเวณรอยเลื่อนคลองมะรุ่ยด้านตะวันออก จังหวัดสุราษฎร์ธานี ประเทศไทย

Thesis (M.Sc., Geophysics)--Prince of Songkla University, 201

Potential of Eisenia fetida (Redworm) for the conversion of three varieties of organic waste

Purpose The aim of this study was to assess the potential of Eisenia fetida (Redworm) in composting different types of waste, namely tea waste (TW), vegetable waste (VW) (leaves of cauliflower), and mixed food waste (MFW).Method The experiment was set up inside the Lab room during the summer. For vermicompost preparation, 27 equal size vermi beds of moist sawdust were prepared in a tub basin. The organic wastes were separately fed to earthworms along with 10 grams of bonemeal and 10 grams of eggshell powder as supplemented materials. The mature worms, offspring, and cocoons were then counted after 14 weeks of the experiment. Moisture and pH of vermicompost were measured in the laboratory.Result The results show that Eisenia fetida preferred tea waste more than vegetable and mixed food waste. The total number of earthworms, including young, increased by 7.13 times in Tea waste with Bonemeal (TW-BM). In mixed food waste composting, the total number was increased by 3.06 times, and mature worms were increased by 0.21times in MFW-ES. However, all worms died in vegetable waste due to high pH and moisture. The productivity of vermicompost was higher in tea waste ranging from 39.86±0.59% (TW-C) to 43.64±2.75% (TW-ES).Conclusion The study concluded that a large number of leafy vegetables are not suitable for the health of earthworms. Significant results were obtained regarding the number of mature worms, offspring production, changes in the total number of worms, number of cocoons, and productivity of vermicompost among three kinds of waste composted

Methodological approach for dating harbor sediments by using luminescence datinga case study in Ephesus, Western Turkey

For this study, a 15-m sediment core from the Roman harbor of Ephesus has been dated with the luminescence technique. C-14 age estimates from the same and a neighboring core were used for comparing and validating the luminescence dating results via a single aliquot regenerative dose (SAR) protocol: infrared stimulation of polymineral and blue stimulation of quartz. The results reveal new insights into the deposition of the sediments of the Roman harbor from 2000 BC to AD 1500 approximately. Some samples showed incomplete bleaching. The difference between the polymineral and the quartz techniques described the bleaching condition before burial. When both approaches give consistent ages, complete bleaching can be assumed. Consistent ages were further applied to the Bayesian age-depth model and discussed within the archeological context. Based on the Bayesian age-depth model, a high sedimentation rate of ca. 65mm/year was calculated for the period of similar to 700-400 BC suggesting a fast advance of the delta front. However, other age estimates suggest a fast advance for the period 200 BC to ca. AD 100. This is probably due to incomplete bleaching of the luminescence samples and the use of bulk samples for C-14 for this new study. Comparing the results with nearby cores suggests that dredging was conducted in the southern part of the Roman harbor at a depth of ca. 5m b.s.l

Dry-Season Soil and Co-Cultivated Host Plants Enhanced Propagation of Arbuscular Mycorrhizal Fungal Spores from Sand Dune Vegetation in Trap Culture

The use of arbuscular mycorrhizal fungi (AMF) as biofertilizer in agriculture is a sustainable approach to fertilization. The first step in the production of AMF biofertilizer is inoculation of mycotrophic plants with a composite of soil and native plant roots, containing potentially viable AMF spores from natural habitats, to a trap culture. A single host plant or a consortium of host plants can be used to propagate AMF spores. However, the difference in the comparative efficiency of mono- and co-cultivated host plants used for the production of AMF spores and the maintenance of original AMF community composition has not been well elucidated. Here, we prepared trap culture with nutrient-poor soil from coastal sand dune vegetation collected during the dry season when the AMF spore density and relative abundance of Glomeromycota ITS2 sequences were significantly higher (p = <0.05) than in the wet season. The AMF communities in the soil were mainly composed of Glomus spp. Maize (Zea mays L.) and/or Sorghum (Sorghum bicolor (L.). Moench) were grown in trap cultures in the greenhouse. Our results demonstrated that co-cultivation of the host plants increased the production of AMF spores but, compared to mono-cultivation of host plants, did not better sustain the native AMF community compositions in the coastal sand dune soil. We propose that the co-cultivation of host plants in a trap culture broadens AMF-host plant compatibilities and thus sustains the symbiotic association of the natively diverse AMF. Therefore, the results of this study suggest that further research is needed to confirm whether the co-culturing of more than one host plant is as efficient a strategy as using a monoculture of a single host plant

Occurrence of Microplastics in River Water in Southern Thailand

Microplastic (MP) contamination in the marine environment has received growing attention. In 2022, the surface water of the U-Taphao River was sampled four times, in February, April, June, and August. The surface water samples were taken at seven different locations, ranging from upstream to downstream parts of the river. The results reveal that the number of MPs detected at the U-Taphao River in February, April, June, and August were 0.41 ± 0.08, 0.25 ±0.06, 0.24 ± 0.11, and 0.26 ± 0.06 particles/L, respectively. The MPs in the U-Taphao River each month were not statistically different (p = 0.190). The trend of the number of MPs found declined from upstream to downstream. Fibers were the most commonly found MPs in the U-Taphao River in this study and were found at more than 80% of all stations during all sample collection periods. Our results indicate that MP contamination is present in the river water, but it is noted that slightly different polymer types were found during each collection month. MPs can be transferred through the food chain and potentially to humans. Regular monitoring of MPs in the riverine system is, therefore, important, for which the findings of the present study can be used as a baseline for the number of MPs in the river water in the region

Relative Sea Level Trends for the Coastal Areas of Peninsular and East Malaysia Based on Remote and In Situ Observations

Absolute sea-level rise has become an important topic globally due to climate change. In addition, relative sea-level rise due to the vertical land motion in coastal areas can have a big societal impact. Vertical land motion (VLM) in Southeast Asia includes a tectonically induced component: uplift and subsidence in plate boundary zones where both Peninsular and East Malaysia are located. In this paper, the relative sea-level trends and (seismic cycle-induced) temporal changes across Malaysia were investigated. To do so, the data (1984–2019) from 21 tide gauges were analyzed, along with a subset (1994–2021) of nearby Malaysian GNSS stations. Changes in absolute sea level (ASL) at these locations (1992–2021) were also estimated from satellite altimetry data. As a first for Peninsular and East Malaysia, the combination ASL minus VLM was robustly used to validate relative sea-level rise from tide-gauge data and provide relative sea-level trend estimates based on a common data period of 25+ years. A good match between both the remote and in situ sea-level rise estimations was observed, especially for Peninsular Malaysia (differences < 1 mm/year), when split trends were estimated from the tide gauges and GNSS time series to distinguish between the different VLM regimes that exist due to the 2004 Sumatra–Andaman megathrust earthquake. As in the south of Thailand, post-seismic-induced negative VLM has increased relative sea-level rise by 2–3 mm/year along the Andaman Sea and Malacca Strait coastlines since 2005. For East Malaysia, the validation shows higher differences (bias of 2–3 mm/year), but this poorer match is significantly improved by either not including data after 1 January 2014 or applying a generic jump to all East Malay tide gauges from that date onwards. Overall, the present relative sea-level trends range from 4 to 6 mm/year for Malaysia with a few regions showing up to 9 mm/year due to human-induced land subsidence

Monitoring Megathrust-Earthquake-Cycle-Induced Relative Sea-Level Changes near Phuket, South Thailand, Using (Space) Geodetic Techniques

Temporal changes in vertical land motion (VLM) in and around Phuket Island in southern Thailand following the great 2004 Sumatra–Andaman megathrust earthquake have impacted the relative sea-level change estimates based on tide-gauge (TG) records. To better monitor the VLM, two new continuous global navigation satellite system (GNSS) stations have been installed in the past 5 years, situated on bedrock both near and at the Koh Taphao Noi Island TG in Phuket, which together with older global positioning system (GPS) data provides a clear insight in the VLM of Phuket Island from 1994 onward. In addition, satellite altimetry (SALT) data has been analyzed since 1992. The VLM (GPS) position and relative (TG) and absolute (SALT) sea-level change time series were successfully combined in pairs to validate each independent result (e.g., SALT − GNSS = TG): prior to the 2004 earthquake, the relative sea-level rise in Phuket was 1.0 ± 0.7 mm/yr, lower by 2.4 ± 0.2 mm/yr than the absolute sea-level rise caused by VLM. After the earthquake, nonlinear post-seismic subsidence has caused the VLM to drop by 10 cm in the past 17 years, resulting, by the end of 2020, in a relative sea-level rise by up to 16 cm. During the same period, other TG stations in south Thailand recorded similar sea-level increases. Combination with SALT further suggests that, prior to 2005, uplift (5.3 ± 1.4 mm/yr) of the coastal region of Ranong (north of Phuket) resulted in a relative sea-level fall, but since then, post-seismic-induced negative VLM may have significantly increased coastal erosion along the entire Andaman Sea coastlineAstrodynamics & Space Mission