The integrated application of high-resolution gravity and magnetic methods has proven effective in detecting and mapping buried archaeological structures at the Gunong Biram Fortress site in Aceh Besar. The research aims to map subsurface archaeological structures and validate geophysical anomalies through targeted excavations. A CG-5 gravimeter and GSM-19 proton-precession magnetometer were deployed over 5600–5900 m² with 2 m spacing inside the 28 × 28 m fort and 3 m outside. The Complete Bouguer anomaly ranges from 80.5 to 83 mGal, with low values (< 80 mGal) inside the fort, while higher values (> 82 mGal) and steep gradients appear along the southern and eastern edges, aligning with the cliffs formed by the Seulimeum fault. Total magnetic intensity ranges from − 600 to + 600 nT, with higher amplitudes near the preserved fort remains. To clarify the anomalies’ spatial distribution, we applied filters like derivatives, tilt angle, and analytic signal. These highlight edges and linear trends matching the fort-wall geometry and NW-SE trend. Euler deconvolution (SI = 0) shows that most sources cluster between 1 and 3 m in depth, with a few < 1 m, indicating shallow origins. Excavation of six trenches revealed column-like stone features, a buried wall parallel to the remains, and dispersed rubble aligned with the wall, within the upper meters and beyond the visible fort outline. The spatial correlation of anomaly patterns, Euler depths, and excavation results confirms extensive shallow masonry around the fort platform, highlighting the value of combining methods for archaeological prospection in active volcanic terrains.

This study presents a geochemical investigation of sediments associated with the 2004 Indian Ocean tsunami collected from Pulot Village, Aceh Besar Regency, Indonesia, one of the area most severely affected by the event. The analysis was performed using calibration-free laser-induced breakdown spectroscopy (CF-LIBS). A pulsed Nd:YAG laser operating at 1064 nm (56 mJ, 10 ns) was directed onto the sediment surface to generate plasma emission, allowing rapid identification of elemental constituents. Under near-local thermodynamic equilibrium conditions, the generated plasma exhibited stable characteristics, enabling the detection of a wide range of elements. These include major salt-forming elements (Ca, K, Mg, Na, Al), metallic and trace elements (Si, Fe, Ti, Ba, Sr, Cu, Cr, Pb, Mn, Ni, V), as well as light elements of organic origin (C, H, O, and N). Significant compositional contrasts were primarily associated with fluctuations in Fe, Cu, and Cr concentrations. Iron was predominantly identified within the tsunami and paleosoil layers, particularly within the 230-280 nm wavelength range, while only minor signals were occasionally detected in the topsoil. In contrast, Cr and Cu were nearly absent in both the topsoil and paleosoil horizons, providing a clear geochemical distinction for the tsunami deposit layer. Quantitative determination using CF-LIBS demonstrated strong agreement with XRF measurements. However, LIBS showed superior analytical performance in terms of rapid multi-element detection and its capability to identify light elements (C, H, O, N) and several trace heavy metals (Ba, Cu, Cr, Pb, Ni, V) that are less effectively detected by XRF. Elemental concentration ratios within the tsunami layer, particularly Si/Ti, Ca/Ti, and Al/Ti, exhibited distinct patterns compared to surrounding strata, highlighting their suitability as geochemical proxies for identifying tsunami-derived sediments. Overall, the findings emphasize the effectiveness of LIBS as a rapid, reliable, and versatile technique for both qualitative characterization and quantitative assessment of tsunami deposits.

Lokop is a geothermal potential located on the island of Sumatra, Indonesia. It is readily accessible and surrounded by a large population and many emerging business districts. This setting highlights the significant economic potential of the Lokop geothermal field. The government of Indonesia has also pledged a strong commitment to developing green and renewable energy initiatives, including geothermal as one of its priorities. These favorable conditions are ideal for developing a geothermal power plant in the Lokop field. Despite these benefits, the geological framework and geophysical properties of the Lokop prospect remain insufficiently constrained, and published scientific studies on this area remain markedly limited. This research aims to address the existing knowledge gap and was conducted to achieve two main objectives.: (1) to map hydrothermal alteration zones within the Lokop geothermal prospect; and (2) to map fault zones across the study area. In this study, gravity data were used to evaluate fault zones and fracture systems within the Lokop geothermal prospect. Landsat data were used to map the hydrothermal alteration zones. The gravity-based analysis successfully showed the spatial distribution of faults and fracture systems across the Lokop field. Low-gravity Bouguer values (-20 to -15 mGal) were observed within the Lokop field and are interpreted as indicative of porous rocks containing hydrothermal fluids. Furthermore, the Landsat analysis showed the presence of hydrothermal alteration zones, with the altered minerals-primarily iron oxides, kaolinite, and chlorite-identified mainly in the hot spring areas. Time-series evaluation of surface temperature further reveals that the Lokop hot spring is characterized by temperatures ranging from 36 to 38.5 °C, with the lowest recorded in 2023 and the highest in 2020, indicating an increased heat supply from the geothermal reservoir. We believe that the results of this research offer essential insights for enhanced characterisation of the geothermal system in the Lokop field.

The Beekeeper Formation is known as a proven reservoir in the Woodada Gas Field, Perth Basin, Australia. The primary porosity of this formation is of low quality, and hydrocarbon were produced mainly from secondary fracture porosity. Even though a significant amount of gas has been produced from Beekeeper Formation, much is not known about its fracture systems. This study attempts to fill this gap and aims to better understand the evolution and development of the fracture systems of the Late Beekeeper Formation. characterization of the Beekeeper fracture systems was carried out on three wells (Beekeeper-1, Woodada-3, and Woodada-14) using the scan-line method and observation of the available cores. Results show that the Beekeeper Formation has spectacular multi-size and multi-episode fracture systems that were fully/partially infilled with calcite cement. Size of fracture’s aperture ranges from <1mm up to 1.5 m. Majority of the fracture systems in the Beekeeper Formation are sub-vertical oriented. The fracture systems of the Beekeeper Formation are dominated by straight and arched morphology. The development of these fracture systems is interpreted to be associated with the extensional-transtensional evolution of the Perth basin, which was strongly influenced by various tectonic processes that occurred mainly during Mesozoic. The presence of fracture systems within the Beekeeper Formation provides a migration pathway for hydrocarbon and compensated the poor primary porosity. A better understanding of these fracture systems is expected to provide new insights into the development of fractured reservoirs and may benefit hydrocarbon exploration and production processes.

This research is based on the need for Marine Automatic Weather Station (MAWS) devices for climate change monitoring based on the Internet of Things (IoT) which are still lacking and are supplied from abroad. This research is limited to wind speed and direction parameters. The resulting wind speed and direction data will be saved into a database and displayed on a 16x2 LCD and a dynamic website using PHP, CSS, HTML, JavaScript, and SQL programming. The data transmission is using the 2G/3G cellular network so that the device could be placed in areas where there is only a 2G/3G cellular network. This instrumentation system consists of several parts, such as a data processing unit using the Arduino Uno microcontroller. This instrument is also equipped with a SIM808 GSM/GPRS/GPS module. In this research, there are two stages of equipment testing, i.e. laboratory testing to determine whether data can be sent in real-time into the database, and field testing which functions to calibrate the equipment. The error value of the wind speed measuring instrument is 2.48 % and the accuracy is 97.52%, so the designed instrument can be said to be accurate. Meanwhile, the wind direction measuring instrument has a high error value of 21.93 % and an accuracy of 78.07%.

We conducted an extensive geohazard survey along 200 km of coastline in Bengkulu and Lampung provinces, Sumatra, Indonesia, focusing on paleotsunami deposits. Our study involved coring at 11 coastal sites, with a particular emphasis on exploring diverse coastal environments, including coralline shores behind reef platforms, coastal wetlands and river floodplains. At the northern end of our study area, near Bintuhan, we documented a significant palaeo-tsunami deposit within a former coastal wetland now converted into a padi field. This deposit was clearly identified across several trenches in two transects separated by ~200 metres. At the southern end of the survey, we found abundant evidence of the 1883 Krakatoa eruption tsunami at three sites within Semangka Bay, directly facing Anak Krakatau volcano. Interestingly, despite investigating numerous intermediate sites, we did not find any additional palaeotsunami evidence. This suggests possible regional variability in tsunami occurrence along this section of the Sumatran coastline. Our results raise the possibility that this region may not experience the same frequency or magnitude of tsunamigenic earthquakes as the Acehnese coastlines at the northern end of Sumatra, where there is now well-established evidence for large tsunamis recurring at approximately 500-year intervals. While we accept that it is possible that all seven sites we investigated in between, on the west coast of Lampung province, happened to have no preserved evidence, we raise the possibility that an alternative explanation is that this stretch of coastline does not experience earthquakes large enough to generate a tsunami that in turn has a wave high enough to be preserved in the coastal sediments. We believe that our study merits further investigation of the sedimentological record of paleotsunamis in this region, and the wider implications for regional seismicity characteristics.

Kuta Lubok is one of the archaeological heritage sites of the Lamuri Sultanate in Aceh, dating back to the 13th century. The site has experienced significant damage over time, primarily due to the Indian Ocean tsunami and natural erosion, which has led to the partial destruction and burial of structural remains. To support preservation and reconstruction efforts, a non-destructive geophysical approach was deemed necessary to locate and map the buried features of this historical site. Geophysical methods, including magnetic, VLF-EM, and EM induction techniques, were applied to investigate the subsurface conditions and identify the distribution of archaeological remains. A total of 22 survey profiles, each ranging from 60 to 80 meters in length, were conducted across the fort and adjacent areas of archaeological interest. Fraser's analysis of VLF-EM data revealed the distribution of archaeological traces, with high tilt values on the west side indicating the location of the Kuta Lubok fort. Measurements between 80 and 400 meters suggest the presence of a road leading to the fort. VLF-EM data also show that archaeological remains are buried at depths between 0 and 5 meters, a range consistent with the Euler Decomposition results obtained from magnetic data collected along the same profiles. In the form of apparent conductivity, EM induction data identified the fort's distribution, albeit with lower resolution. Magnetic susceptibility data from EM induction confirmed similar findings. The excavation results in the fort area have found several archaeological objects such as pottery, stoneware, ceramics, charcoal, and bones, indicating that the Kuta Lubok building was once a community settlement area. This research demonstrates the value of integrating multiple geophysical methods to enhance archaeological investigations and preservation planning in coastal heritage sites. Overall, the combined geophysical and archaeological analysis suggests that the Kuta Lubok fort extends approximately 400 meters eastward, parallel to the coastline, from the remaining visible structure.

The Beekeeper Formation, a mixed carbonate-siliciclastic reservoir, has long been known as a proven gas reservoir in the northern Perth Basin, Australia. However, its characteristics, and spatio-temporal distribution are still not well understood. There are two main objectives of this study: (1) to identify the main cutting facies groups/subgroups, and electrofacies of the Beekeeper Formation; and (2) to understand spatio-temporal characteristics, and development of the Beekeeper Formation. Integrated multi analyses have been conducted to achieve these objectives including cutting, wireline logging, and XRF analyses. Fifteen types of cutting components, and nine electrofacies were identified forming the Beekeeper Formation. The Beekeeper Formation consists of nine facies sub-groups, and these are classified into carbonate-dominated facies group, siliciclastic-dominated facies group, and mixed carbonatesiliciclastic facies group. Furthermore, this formation can vertically be divided into three parts on the basis of the main facies groups: the lower, middle, and upper parts. The lower and upper parts consist predominantly of siliciclastic materials, while the middle part is dominated by carbonate materials. In the north of the study area, the Beekeeper Formation consists predominantly of siliciclastic materials with minor carbonate materials, whereas in the central to south it consists mainly of carbonate material with minor-moderate siliciclastic materials. Various processes have influenced the evolution of the Beekeeper Formation including influx of siliciclastic components, mixing of carbonate and siliciclastic materials, suitable environment for the growth of carbonate biotas, sea level fluctuation, and tectonic activities. It is expected that findings from this study will provide new insights into characteristics of mixed carbonate-siliciclastic reservoirs in general, and will have regional and global applicability. (c) 2025 The Authors. Publishing services provided by Elsevier B.V. on behalf of KeAi Communication Co. Ltd. This is an open access article under the CC BY-NC-ND license (http://creativecommons.org/licenses/ by-nc-nd/4.0/).

The Aceh River delta, northern Sumatra, is a subject of interest since the coastline was struck, more than any other, by the 2004 Indian Ocean Tsunami, the largest recorded in human history. Thereafter, significant scientific efforts focused on short-term dynamics to address the environmental effects of the tsunami, but the long-term evolution of the delta in this specific context of volcanic eruptions, megathrust earthquakes and tsunami landing, however, remains to be understood. This study investigates the subaerial delta, based on shallow sediment borehole stratigraphies and C-14 ages, in order to provide a partial reconstruction of the western and eastern fluvial and coastal evolution over the past 7 ky. It also benefits from comprehensive resistivity maps produced during recent helicopter-borne electromagnetic (HEM) surveys, and from earlier geomorphological mapping. By prograding, the delta expanded seaward, exposure to swell increased, and a large strandplain accreted along the eastern delta front from 4 to 1 ky BCE. The delta thus evolved asymmetrically, with higher, tightly-stacked beach ridges in the east, which accreted at similar to 6 km(2)/ky. Meanwhile, the Aceh River remained stable, along the western side of the delta, burying the western strandplain under its floodplain. After 0.5 ky BCE, delta progradation increased to similar to 14 km(2)/ky, generating low-lying and wider spaced beach ridges to the east. A series of river avulsions between 0.2 ky BCE and 1.6 ky CE shifted the river course from the west to the center of the delta. An asymmetric cuspate promontory grew at 23 km(2)/ky after 0.5 ky in front of the current mouth of the river, projecting 1 km offshore of the current coastline, before undergoing erosion in the past few centuries. Here, we discuss which combination of global and local factors, including sea level change, sediment supply, wave climate, tectonics, land use and tsunamis may explain the most salient processes during the growth of the Aceh River delta. Beyond its local interest, this study provides clues for a wider understanding of the complexity of subaerial delta development.

The Ek Leuntie Cave is a prospective paleotsunami geopark that preserved 12 tsunami layers dating back 7500 years in Aceh. Landslides pose many challenges to the development facilities in karst areas. Before development, the area was assessed using high-resolution Ground Penetrating Radar (GPR) and Electrical Resistivity Tomography (ERT). The 700 and 250 MHz of GPR frequencies were used to image shallow subsurface structures, while the ERT method can penetrate deeper. Data measurements were conducted on a long 130m profile perpendicular to the cave entrance. The GPR radargrams clearly show subsurface structure up to 1.5 m depth. The uppermost thin and flat layer is superimposed on a concave layer. The lowest structure begins to fade due to the limitation of penetration depth. The ERT model images up to 30 m depth with resistivity vary 0 to 1000 Ωm. The uppermost and the second layers have low to medium resistivity values superimposed by a very high resistivity layer. The top layer filled with anthropogenic soil covers the sandy layer at a depth of 0.3 to 0,4 m. While the third layer is interpreted as limestone. Shallow borehole data drilled along the profile agree with the interpretation. The 700 MHz of GPR radargram shows a very clear interface between the sandy and the top soil layers as well as the limestone beneath it, while the ERT model penetrates deeper but the interface between layers is blurry due to smoothing effects. Both methods complement each other and can be used for geotechnical assessment of the area.

Ek Leuntie Cave is a karst cave in Meunasah Lhok, Lhoong District, Aceh Besar Regency. This cave is very rare. It has 12 tsunami layers dating back 7500 years. These layers need to be preserved as a paleotsunami geopark in Aceh. However, there are many challenges to developing public facilities in karst areas, such as sinkholes and landslides. Therefore, this study aims to investigate the potential hazards in the area by using the Ground Penetrating Radar (GPR) method at 700 MHz and 250 MHz frequencies. The GPR method is used because of its ability to image shallow subsurface structures with high resolution. The GPR method was used on 7 survey lines around Ek Leuntie Cave. The resulting radargrams are then processed using GPRPy software to clarify the reflection signal. GPR interpretation at 700 MHz and 250 MHz frequencies produces the same radargram at a very shallow depth, but the boundaries between layers are clearer at 700 MHz. Core data from multiple samples supports GPR interpretation. Based on the core data, the compact layer is located in the sandy soil layer, while the less compact layer is located in the old main road before the tsunami layer and in the bedrock. The less compact layer has potential hazards such as subsidence. The area is located in the west to south of the cave. Based on the GPR radargrams obtained, the investigation area is dominated by clay fill, sandy soil, clayey sand and bedrock. The results of the study are expected to be used as a reference for mitigation in the development of the Ek Leuntie Cave Geopark.

The interaction process between the atmosphere and the ocean that occurs in the Pacific Ocean and the Indian Ocean has a major impact on climate and weather conditions in Indonesia. The phenomenon that arises due to this interaction is known as El Nino - Southern Oscillation (ENSO). In addition to ENSO, other mechanisms also impact weather and climate change in Indonesia, including the Indian Ocean Dipole (IOD). This study aimed to analyze the effect of ENSO and IOD on rainfall in the Aceh region. The data used were CHIRPS rainfall data with the locations of four meteorological stations and one climatology station in Aceh, IOD index data and ENSO index data. Data processing in this study was carried out using Grid Analysis and Display System (GrADS) software and Spreadsheet for CHIRPS rainfall data, followed by processing ENSO index data and IOD index using Spreadsheet software. The analysis showed that the ENSO phenomenon has a longer occurrence than the IOD phenomenon. ENSO has a greater influence on rainfall in the Aceh region than IOD, especially La Nina, which has a weak to moderate correlation. Negative IOD and El Nino phenomena influence several observation points, but some stations do not show a correlation between rainfall and the index. The positive IOD phenomenon is strongly negatively correlated with rainfall at the observation station, which shows that positive IOD does not influence the Aceh region.

Ek Leuntie Cave, in the southern city of Banda Aceh, Aceh Province, is recognized as an educational media based on geopark sites because it holds a 7400-year paleotsunami track record. As a karst area, Ek Leuntie Cave is vulnerable to the impact of geological disasters such as earthquakes, sinkholes and subsidence. As an effort to reduce the negative impact of geological disasters, geophysical studies have been applied in the Ek Leuntie Cave Karst area. The study aims to identify the subsurface geological structure of the Karst area. The identification was carried out using the Electrical Resistivity Tomography (ERT) method of Wenner-Schlumberger configuration applied to two measurement trajectories that have South-North and West-East directions in front of the Ek Leuntie Cave door. ERT data acquisition results were then modeled in inversion using Res2Dinv software to produce a 2D model of the subsurface geological structure of the Ek Leuntie Cave karst area based on variations in rock resistivity values. Interpretation of subsurface geological structure modeling is validated with shallow drilling data (Hand Auger). The inversion modeling results show that the rock resistivity value in the Ek Leuntie Cave area reaches a depth of 30 m which has a resistivity value of 0 - 1000 Ωm. The results of the interpretation of resistivity values and validation of drill data show that the Ek Leuntie Cave area is covered by a layer of sand with fine to coarse texture and the layer below is a layer of limestone at a depth of ± 0.4 meters with a resistivity value of 50 - 250 Ωm. Limestone generally shows porosity with the possibility of caves or pores in the rock formation at Ek Leuntie Cave, making it vulnerable to damage from earthquakes, landslides, and subsidence. The results of the study are expected to provide updated information in efforts to develop the Ek Leuntie Cave geopark area.

The Boreal Summer Intraseasonal Oscillation (BSISO) is intraseasonal climate variability in addition to the Madden-Julian Oscillation (MJO) that affects weather and climate in the Indo-Pacific region including the Province of Aceh. The impact of BSISO on extreme rainfall and flooding in Aceh needs to be investigated to enhance preparedness, mitigation, and adaptation strategies against its negative impacts. The datasets use in situ daily rainfall data from 5 BMKG stations in Aceh and the BSISO indices (BSISO1 and BSISO2) during the extended boreal summer (May–October) period 2001–2020, as well as flood event data in Aceh from 2008–2020. The results of this study show that rainfall in Aceh province is influenced by BSISO variability and has the potential to increase extreme rainfall and even cause flooding in some areas in Aceh, depending on the propagation path of BSISO. The frequency of extreme rainfall in Aceh during BSISO is identified using daily rainfall beyond the 95th percentile in each BSISO phase, which increases the probability of extreme rainfall in Aceh by around 20–100% during phases 1-3 in both BSISO1 and BSISO2. During BSISO1, the probability of flooding in phases 1-3 increased by up to 90%, and BSISO2 also increased the probability of flooding in phases 1-4 by up to 72%.

Earthquakes and tsunamis natural disasters have repeatedly occurred on the coast of Aceh province, which lies between the confluence of two plates. The tsunami deposits in this area can provide important information regarding the reconstruction of marine attacks by past earthquakes and tsunamis. In general, tsunami deposits can be identified based on their geological, sedimentological, paleontological, and geochemical characteristics. In our research work, spectrometry X-ray fluorescence (XRF) has been utilized to investigate the geochemical signatures of tsunami-affected soil samples in Aceh province at three tsunami-impacted areas, namely Aceh Besar regency, Banda Aceh City, and Aceh Barat regency. The sampling point is located about a kilometer from the coastal line. Our findings indicate that tsunami-affected soils in Aceh Province after 10 years struck by tsunami contain terrestrial markers such as Fe and Ti, carbonate markers (Mg, Ca), and heavy metals elements (Cr, Ni, Cu, Zn, and Sr). On the other hand, in our study, the concentration ratios of several elements such as Si/Ti and Ca/Ti seem most suitable as a chemical signature for differentiating environmental conditions such as the 2004 Indian Ocean tsunami event. It could be noticed that geochemical analysis by XRF can be applied to characterize the tsunami-affected soils in several coastal areas of Aceh province.

The heterogeneities of mixed carbonate-siliciclastic reservoirs are not well understood, despite the importance of this type of deposit as a proven hydrocarbon reservoir in many oil and gas fields. This study aims to advance our understanding of the heterogeneities of the mixed carbonate-siliciclastic reservoir with three main objectives: (1) to characterize sedimentary facies and depositional environment of the Beekeeper Formation; (2) to better understand the mixing of siliciclastic and carbonate materials; and (3) to better understand the main influences on the development of a mixed carbonate-siliciclastic reservoir. Integrated geological analyses (sedimentary logging, acetate peels, acid digestion, and petrographic) have been conducted to achieve the aim and objectives of this study. Results show that the Beekeeper Formation consists of seventeen facies grouped into carbonate-dominated facies group, siliciclastic-dominated facies group, and mixed carbonate-siliciclastic facies group, and was deposited within a ramp type platform. Both compositional and stratal mixing were identified as present within the Beekeeper Formation. The mixing of carbonate and siliciclastic materials/minerals within this formation occurred at three different scales, which are small scale (mm to cm scale), moderate scale (cm to a few m scale), and large scale (a few m to >100 m scale). The presence of fracture systems, highly varied facies, and the mixing of carbonate and siliciclastic materials/minerals are evident in the evolution of the Beekeeper Formation which was strongly influenced by tectonic activities, climatic conditions, eustasy, sea-level fluctuations, rate of carbonate production, and terrigenous influx.

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.

Laser-induced breakdown spectroscopy (LIBS) was employed to characterize the geochemical signatures layer by layer of 2004 Indian Ocean tsunami deposits in Seungko Mulat Village, Aceh Province, Indonesia. In the LIBS experimental setup, a Nd-YAG laser beam is directed towards the deposit samples, and the resulting atomic emission lines from the laser-induced plasma are captured using a spectrometer. Our analysis reveals terrestrial indicators (Fe), heavy metals (Cu, Cr, Co, Cd), and increased emission intensity of Mg, Ca, Al, K, Si, Ba, N, and O in the 2004 Indian Ocean tsunami layers. The emission intensity ratios of several elements in the 2004 Indian Ocean tsunami deposit layers, namely Ca/Ti, Si/Ti, and K/Ti, unveil notable disparities among the elements evaluated. This indicates the possibility of utilizing these ratios as reliable geochemical markers to differentiate the layer by layer of tsunami deposits. LIBS surpasses XRF in detecting nearly all elements simultaneously and identifying both light elements and specific heavy metals (Ba, Cu, Cr, Co, Cd, Pb, Ni, V, W), exceeding XRF's detection capabilities. This study emphasizes the effectiveness of LIBS as an advanced optical technique, offering speed and promise in analyzing layer-by-layer geochemical markers of the 2004 Indian Ocean tsunami deposits in Seungko Mulat Village.

The construction of the Banda Aceh Wastewater Treatment Plant has been delayed due to the discovery of archaeological artifacts in the construction area. In an effort to protect the existence of archaeological artifacts, a survey using the magnetic method was carried out to identify the distribution of archaeological artifacts. Total magnetic field intensity data were measured using the Proton Precession Magnetometer (PPM) equipment. The measuring area is 38 m × 40 m with 1599 measurement points and the distance between the points is 1 m. Total magnetic field anomaly values were obtained through the diurnal and International Geomagnetic Reference Field (IGRF) corrections. The maximum values of the total magnetic field anomaly are 71.0 nT and the minimum values are -99.5 nT. The maximum and minimum values are close to where the artifacts have been exposed. To obtain the distribution of anomalies, analysis signal processes were performed. The results succeeded in showing the existence of archaeological artifacts based on elongated and closed anomalies. Elongated anomalies were identified as a fence structure called diwai in Acehnese culture and the closure anomalies were identified as gravestones. The existence of these archaeological artifacts and their historical values need to be preserved so that they will be educational facilities and historical tourism objects for the community.