Influence of vegetation type on infiltration rate and capacity at Ie jue geothermal manifestation, Mount Seulawah Agam, Indonesia.

Ie Jue is one of the geothermal manifestation of hot water and fumaroles in the northern zone of Mount Seulawah Agam. Because hot water in the Ie Jue manifestation is derived from meteoric water, the presence of Ie Jue hot springs is determined by rain intensity and surface infiltration rates in the vicinity of the manifestation. The purpose of this research is to determine the rate of precipitation infiltration and its link to the type of flora that grows around the manifestation. Ie Jue. The 100 m line transect approach was used to determine sampling locations. Transects were placed in stratified sampling based on the four cardinal directions from the manifestation's center, namely east, south, west, and north. In each transect, three sampling stations were placed at intervals of 0 m, 50 m, and 100 m from the manifestation's midpoint. In each transect, three sampling stations were placed at intervals of 0 m, 50 m, and 100 m from the manifestation's midpoint. At each sampling point, the vegetation type was identified, and soil temperature, moisture, pH, texture, density and organic C were measured. A single ring infiltrometer was used to quantify infiltration rate at each sampling location, and the Horton equation was used to compute infiltration capacity. The results showed that the type of tree vegetation found in the south had the maximum infiltration rate of 54 cm/h - 28.8 cm/h with a constant interval of 40 min, followed by an infiltration rate of 44.4 cm/h - 8.4 cm/h for 45 min in the north with pole vegetation type. In comparison to other regions, the south and north have exceptionally quick infiltration criteria (36.87 cm/h and 29.88 cm/h, respectively). When compared to poles, shrubs, and herbs, tree-type vegetation had the highest infiltration rate. The results showed that vegetation type, soil moisture, bulk density, and soil organic C are the most important elements influencing infiltration in the Ie jue hot spring area.

Suspended sediment transport generated by non-hydrostatic hydrodynamics in Northern Waters of Aceh, Indonesia.

Suspended Sediment transport in the Northern Waters of Aceh is investigated in the domains between 5.4° - 5.65° N Latitude and 95.15° - 95.45° E. Therefore, this study aims to calculate the suspended sediment transport using a non-hydrostatic hydrodynamic model with an output distribution of total suspended sediment concentration. The model was run using tidal components of M2, S2, K1, O1, N2, K2, P1, Q1 and the wind every 6 h in February and August 2019 representing the North East and South West monsoons, as well as sea temperature and salinity data. The results of the model correlated with the Tide Model Driver data obtained, and the simulation results indicated the current in February 2019 is different than in August. The numerical simulation results show that the distribution of suspended sediments in Northern Waters of Aceh is driven by currents. Furthermore, the hydrodynamics and the designed model showed that the distribution value of the surface total suspended sediment concentration was lower in August than in February 2019. The verification results of the surface total suspended sediment concentration between the model and the Visible Infrared Imaging Radiometer Suite showed a good match. These results can facilitate the analysis of limited observation and remote sensing data.

Numerical study of tides in the Malacca Strait with a 3-D model.

Malacca Strait (MS) has an important role and potential for many countries. It is a major transportation route for oil and commodities across continents. In addition, various activities such as shipping, fishing, aquaculture, oil drilling, and energy are also carried out in MS. Tides strongly affect the MS environment so that it becomes a major parameter in MS management. This paper is the first study, which presents MS tidal hydrodynamics based on a baroclinic and nonhydrostatic approach. Tidal hydrodynamics in MS and the surrounding waters were assessed using tidal forces, temperature, salinity, and density. This study analyzes the amplitude, phase, current ellipses, and semi-major axis of the tides. These variables are obtained from the simulation results of the three-dimensional numerical models of M2 tides and combined tides (M2, S2, N2, K1, and O1) with nonhydrostatic models. Then the results obtained are verified by observation data. Amplitude and phase of the tidal wave in MS originate from two directions, namely the northern part of MS (Andaman Sea) and the South China Sea (SCS). Tides from the north of MS propagate into the MS, while tides from the SCS travel to Singapore Waters (SW) and the south of MS. This causes a complex residual flow in SW and shoaling in the middle of MS. Shoaling in the middle of MS is characterized by a large amplitude and semi-major, as in B. Siapiapi. The results of this analysis show that tidal waves are dominated by semidiurnal types rather than diurnal types. The M2 current ellipse has dominantly anticlockwise rotation along the west of the MS, while along the east of MS, it has generally a clockwise rotation.

Highly variable recurrence of tsunamis in the 7,400 years before the 2004 Indian Ocean tsunami.

The devastating 2004 Indian Ocean tsunami caught millions of coastal residents and the scientific community off-guard. Subsequent research in the Indian Ocean basin has identified prehistoric tsunamis, but the timing and recurrence intervals of such events are uncertain. Here we present an extraordinary 7,400 year stratigraphic sequence of prehistoric tsunami deposits from a coastal cave in Aceh, Indonesia. This record demonstrates that at least 11 prehistoric tsunamis struck the Aceh coast between 7,400 and 2,900 years ago. The average time period between tsunamis is about 450 years with intervals ranging from a long, dormant period of over 2,000 years, to multiple tsunamis within the span of a century. Although there is evidence that the likelihood of another tsunamigenic earthquake in Aceh province is high, these variable recurrence intervals suggest that long dormant periods may follow Sunda megathrust ruptures as large as that of the 2004 Indian Ocean tsunami.