Ijen Crater Research Articles

PENGEMBANGAN POTENSI PARIWISATA, EKONOMI LOKAL BERBASIS E-COMMERCE KAWASAN WISATA GUNUNG IJEN KAB. BANYUWANGI

The era of globalization make the move into tourism industry's largest and strongest in the financing of the global economy. The development of tourism has three functions Promote the economy; Maintaining the national identity and preservation of function and quality of the environment; foster a love for the homeland and the nation. Rapid technological advances that make more rapid dissemination of information. The purpose of the study is to examine the promotion of e-commerce can increase the number of tourist visits in the tourist area of Mount Ijen and through the increase in traffic would improve the welfare of local communities. The study population was a tourist visitor Mount Ijen by taking the sampling method using a random sampling of 350 samples, data collection techniques using questionnaires and interviews. Methods of qualitative and descriptive analysis using bivariate analysis. The results of this study indicate that the tourism promotion Ijen crater through e-commerce can increase the number of tourist visits. Ijen crater tourism information through the Internet easier and cheaper to obtain travel information. With the increasing number of tourist visits Ijen crater members positive impact on the welfare of local communities, especially sulfur miners who were around tourist sites Mount Ijen.

PENGEMBANGAN POTENSI PARIWISATA, EKONOMILOKAL BERBASIS E-COMMERCE KAWASAN WISATAGUNUNG IJEN KAB. BANYUWANGI

The era of globalization make the move into tourism industry's largest and strongestin the financing of the global economy. The development of tourism has threefunctions Promote the economy; Maintaining the national identity and preservationof function and quality of the environment; foster a love for the homeland and thenation. Rapid technological advancesthat make more rapid dissemination ofinformation. The purpose of the study is to examine the promotion of e-commercecan increase the number of tourist visits in the tourist area ofMount Ijen andthrough the increase in traffic would improve the welfare of local communities. Thestudy population was a tourist visitor Mount Ijen by taking the sampling methodusing a random sampling of 350 samples, data collection techniques usingquestionnaires and interviews. Methods of qualitative and descriptive analysis usingbivariate analysis. The results of this study indicate that the tourism promotion Ijencrater through e-commerce can increase the number of tourist visits. Ijen cratertourism information through the Internet easier and cheaper to obtain travelinformation. With the increasing number of tourist visits Ijen crater memberspositive impact on the welfare of local communities, especially sulfur miners whowere around tourist sites Mount Ijen.

Ecotourism Attractions, Level of Satisfaction and Management of Air Terjun Kembar in Kampung Anyar Village, Banyuwangi

Air Terjun Kembar (Twin Waterfall) in Kampung Anyar, Banyuwangi is an alternative tourist travel destinations around the Ijen crater. This study aims to determine the history, attractions, eco-tourism potential, the level of customer satisfaction and further management for the area. The method is carried out by semi-structured interviews, questionnaires based on the satisfaction level of Sapta Pesona (standard value) and SWOT Analysis to the management. These results indicate that previously Kembar Waterfall Kampung Anyar was used for water resources. Then, in 2014 began to be managed by the group of people in Kampung Anyar. SWOT analysis shows that the management is good. In some aspect however it needs to be improved. Keywords: Ecotourism, Kampung Anyar, Sapta Pesona, SWOT.

Strategic Management of Nature-Based Tourism in Ijen Crater in the Context of Sustainable Tourism Development

The aim of the study is to define the strategic management of nature based tourism in Ijen crater, East Java. From the perspectives of accessibility, problems facing by accessibility are related to the travel distance and forest road quality. Ijen craters have three important aspect in competitiveness tourism aspect, namely something to see (mountain landscape), something to do (trekking, hiking, bird watching), and something to buy (meals). The future development of such attraction should be meets ecotourism principles. This study found that improving tourism facility and infrastructure were important aspects. The development and improvement of tourism facility and infrastructure, however, should be incorporates ecotourism principles. In such a case, the conservation, local people and community development becomes crucial issue. Involvement of stakeholder and local community in facility and infrastructure will increase the quality and sustainability of infrastructure and tourism facility. Keywords: ecotourism strategy, tourism management.

Fumarolic Activity, Acid-Sulfate Alteration, and High Sulfidation Epithermal Precious Metal Mineralization in the Crater of Kawah Ijen Volcano, Java, Indonesia

Abstract Opinion is divided over whether the fluid responsible for the formation of high sulfidation epithermal deposits is a vapor or a liquid, and whether it is entirely volcanic or of mixed volcanic-meteoric origin. Observations made at Kawah Ijen, an active stratovolcano (mainly andesitic in composition) located in the Ijen Caldera Complex in Java, Indonesia, are used to address these issues. The Kawah Ijen crater is approximately 1 km in diameter, and hosts one of the world’s largest hyperacidic lakes (pH ~0). On the lake edge is a small and actively degassing solfatara field, which is surrounded by a much larger area of acid-sulfate alteration. This area was exposed during a phreatomagmatic eruption in 1817, which excavated the crater to a depth of 250 m, and comprises zones of residual silica, alunite-pyrite, and dickite/kaolinite. Based on the fractionation of 34S and 32S between alunite and pyrite, the acid-sulfate alteration occurred at a temperature between 200° and 300°C. High sulfidation epithermal mineralization accompanied the alteration in the form of massive and vein-hosted pyrite that contains up to 192 ppb Au, 9.2 ppm Ag, 6,800 ppm Cu, and 3,430 ppm As; these elements are invisible at the highest resolution of scanning electron microscopy, and thus either occur in the form of nanoparticles or are in solid solution in the pyrite. Condensed fumarolic gases released from the solfatara field and sampled at temperatures between 330° and 495°C contain up to 3 ppm Cu and 3.8 ppm As; the concentrations of Au and Ag are below detection. The pH of the condensed gas (water vapor) is ~−0.5. The above observations support a model in which highly acidic gases condensed ~250 m beneath the floor of the crater. Depending on the fluid/rock ratio, the condensed liquids altered the andesitic host rocks by leaching them to leave behind a residue of “vuggy silica” (high fluid/rock ratio), by replacing the primary minerals with alunite and pyrite (intermediate fluid/rock ratio), or by converting them to dickite/kaolinite (lower fluid/rock ratio). Gold-, silver-, and copper-bearing phases were undersaturated in the condensed liquids. However, they were able to concentrate by adsorbing on the surfaces of the growing pyrite crystals, which developed p-type conductive properties as a result of the uptake of arsenic. The metals were incorporated in the pyrite either by their electrochemical reduction to form native metal nanoparticles or through coupled substitutions with arsenic for iron and sulfur. The results of this study provide compelling evidence that high sulfidation epithermal precious metal mineralization can form directly from condensed magmatic gases.

Extreme alteration by hyperacidic brines at Kawah Ijen volcano, East Java, Indonesia: II: Metasomatic imprint and element fluxes

The hyperacidic brines of the Kawah Ijen crater lake and Banyu Pahit river, East Java, Indonesia, induce an intense alteration on their magmatic host rock. This alteration is a proxy for water–rock interaction in magmatic–hydrothermal systems and associated high-sulphidation mineralizing environments, as well as for how these systems translate changes in the magmatic system to surface emissions, which are used in volcanic hazard monitoring. Detailed bulk chemical study of altered and unaltered samples shows that alteration is characterised by near-complete leaching of all major and trace elements, except for Pb, Sn and Sb, which are progressively enriched (Pb up to 15-fold absolute enrichment). The resulting element release is complementary to the observed changes in composition of the Banyu Pahit water downstream, when corrected for dilution, indicating that alteration progressively increases the element load. The signature of the change in water chemistry is best explained by complete alteration of fresh rock, rather than mature alteration, which might be expected given the advanced altered state of the riverbed. Together with mass balance considerations, this indicates that the dominant element source is material falling into the river from the valley flanks. The chemical signature of the crater lake is inconsistent with the observed alteration in samples from the hydrothermal system, and likewise is best explained by surface input of cations from rocks falling in from the crater walls. This indicates that the lake water cation chemistry is not a direct reflection of the underlying magmatic–hydrothermal system and that its cation content is therefore not an appropriate monitor of changes in volcanic activity.

SCREENING OF THERMOPHYLIC MICROORGANISM FROM IJEN CRATER BANYUWANGI AS PHYTASE ENZYME PRODUCER

Phytase is enzyme which hydrolysis phytic acid to anorganic phosphate and myo-inositol pentakis-, tetrakis-, tris-, bis-, and monophosphate. The use of phytase in feed industry can overcome environment and nutrition problems which were arisen from unmetabolism phytic acid or its salt by poultry, swine and fish. The feed industry needs a thermostable enzyme due to the need of high temperature in pelleting process, i.e. 81 °C. By using thermostabile phytase, the pelleting process will not affect the enzyme activity. Thermostabile phytase can be isolated from microorganism live in hot spring water or volcano crater. In this study, the screening of thermophylic microorganism having thermostabile phytase activity in Ijen Crater, Banyuwangi, has been done. From this process, it was obtained 33 isolates that produce phytase enzyme. Isolate was code by AP-17 yields highest phytase activity, that is 0.0296 U/mL, so this isolate was choosen for further study. The activity of crude phytase enzyme was measured based on the amount of anorganic phosphate that was produced in enzymatic reaction using UV-VIS spectrophotometer at 392 nm. Based on morphology test to identify the gram type of microorganism, isolate AP-17 has a bacill cell type and identified as positive gram bacteria. This isolate was assumed as Bacillus type. Keywords: Phytase, thermophilic microorganism, phytase activity

Impact of acid effluent from Kawah Ijen crater lake on irrigated agricultural soils: Soil chemical processes and plant uptake

Volcanogenic contamination of irrigation water, caused by effluent from the hyperacid Ijen crater lake, has severely affected the properties of agricultural soils in East Java, Indonesia. From a comparison of acidified topsoil with subsoil and with top- and subsoil in a reference area, we identified processes responsible for changes in soil and soil solution chemistry induced by acid irrigation water, with emphasis on the nutrients Ca, Mg, Fe, and Mn, and on Al, which may become phytotoxic under acid conditions in soils. Compositional data for bulk soil composition and selective extractions with 1 M KCl and 0.2 M acid ammonium oxalate are used in a mass balance approach to specify element fluxes, including uptake by rice plants. The results show that input via irrigation water has produced an increase in the total aluminum content in the affected topsoil, which is of the same order of magnitude as the increase in labile Al. High bioavailability of Al, as reflected by concentrations in KCl extracts, is consistent with elevated concentrations observed in rice plants. In contrast, and despite the high input via irrigation water, Ca and Mg concentrations have decreased in all measured soil fractions through dissolution of amorphous phases and minerals, and through competition of Al for adsorption sites on the exchange complex and plant roots. Strong leaching is also evident for Fe and especially Mn. In terms of the overall mass balance of the topsoil, plant uptake of Al, Ca, Fe, Mg and Mn is negligible. If the use of acid irrigation would be stopped and the soil pH were to increase to values above 4.5, the observed phytotoxicity of Al will be halted. However, crops may then become fully dependent on the input from irrigation water or fertilizer for essential elements, due to the previous removal from the topsoil through leaching.

The effect of naturally acidified irrigation water on agricultural volcanic soils. The case of Asembagus, Java, Indonesia

Acid water from the Banyuputih river (pH ∼ 3.5) is used for the irrigation of agricultural land in the Asembagus coastal area (East Java, Indonesia), with harmful consequences for rice yields. The river water has an unusual composition which is caused by seepage from the acidic Kawah Ijen crater lake into the river. This unique irrigation setting allows the study of soil acidification in situ. This paper assesses the effects of volcanogenically contaminated irrigation water on the chemical properties of the agricultural soils. The changes in soil properties were evaluated by comparing samples taken from the topsoil and sub-soil (1–3 m depth) from areas irrigated with acid water and areas irrigated with neutral water. The field survey thus resulted in four soil categories. Bulk soil composition, organic matter content, moisture content and particle size distribution were determined. Reactive phases were quantified with the selective extractions 1 M KCl, 0.1 M Na-pyrophosphate and 0.2 M acid ammonium oxalate (AAO). By comparing the four soil categories it is shown that the use of the naturally polluted irrigation water has had a large influence on the chemical composition of the topsoil. The composition of the soil solution has changed over the entire investigated soil profile. Furthermore the acid irrigation water has strongly modified the composition of the reactive phases, extracted as KCl, pyrophosphate, and AAO extractable elements, and also the bulk soil composition has been significantly modified. Overall this has resulted in the net dissolution of some elements and the net precipitation of others. The changes in the reactive phases and bulk soil composition are only apparent in the topsoil (0–20 cm) but not in the deeper soil.

Macroinvertebrate and algal communities in an extremely acidic river and the Kawah Ijen crater lake (pH 0.3), Indonesia

Acidic aquatic ecosystems are mainly characterized by low pH and high concentrations of metals and other elements with evident effects on local community structure. Acidity effects on benthic communities in one of the world's largest extremely acidic crater lakes, the Kawah Ijen (East Java, Indonesia) (pH <0.3), and the acidic Banyupahit-Banyuputih river (pH 0.7-3.3) originating from it, had not been investigated. Therefore, macroinvertebrate and algal community structure in the acidic river were studied and compared to the neutral rivers Kali Sat and Kali Sengon in the same catchment. The aquatic foodweb of the Banyupahit-Banyputih river was poorly developed and a complete lack of macroinvertebrate species was observed at pH values below 2. At two sampling stations with pH 2.69-3.47 and pH 2.26-2.89 only chironomids were found and other acid-tolerant macroinvertebrate taxa from acidic aquatic systems reported in the literature were absent. No statistically significant differences of metal body burden in chironomids could be detected between locations. In contrast, algal communities were more diversified and the number of taxa increased with increasing pH. Remarkably, high densities of an unknown green alga were found in samples from the acidic crater lake. Diatom communities were characterized by dominance of the acid tolerant Pinnularia acoricola at the most acidic sites, and a gradual replacement by other species with increasing pH. Particular features of the river, such as the lack of aquatic macrophytes and the presence of acid-tolerant algal species (e. g. Euglena mutabilis, Achnanthes minutissima), revealed not only the strength of the acid selection on these communities, but also the role of indirect physical and chemical factors (e. g. high Al, low P concentrations). It is concluded, therefore, that the ability of the studied macroinvertebrates and algal species to withstand the acid circumstances is not only due to their resistance to low pH, but also to the consequences of it.

The impact of the hyperacid Ijen Crater Lake: risks of excess fluoride to human health

The Asembagus irrigation area (East Java, Indonesia) receives a high input of fluoride (F) via surface water that partially originates from the hyperacid crater lake of the Ijen volcano. Endemic dental fluorosis among local residents has been ascribed to F in water wells. In this study, the total F intake by children and adults was estimated, based on concentrations in well waters and foods throughout the area. These values were compared with the Lowest Observed Adverse Effect Level (LOAEL) for dental fluorosis among children and skeletal fluorosis among adults. Fluorosis hazard maps were prepared, identifying the most hazardous locations in the area. It was concluded that there is not only a high risk of dental fluorosis, but also of skeletal fluorosis. Based on the total daily intake, the lowest F concentration in drinking water that poses a risk of developing fluorosis is approximately 0.5 mg/l for dental fluorosis and 1.1 mg/l for skeletal fluorosis. This is below 1.5 mg/l, which is both the guideline value for drinking water from the World Health Organization (WHO) and the Indonesian drinking water standard. This is the first documented case of human health problems that may be directly associated with natural pollutants originating from a volcano-hosted crater lake.

Natural Pollution Caused by the Extremely Acid Crater Lake Kawah Ijen, East Java, Indonesia (7 pp)

Lakes developing in volcano craters can become highly acidic through the influx of volcanic gases, yielding one of the chemically most extreme natural environments on earth. The Kawah Ijen crater lake in East Java (Indonesia) has a pH < 0.3. It is the source of the extremely acidic and metal-polluted river Banyupahit (45 km). The lake has a significant impact on the river ecosystem as well as on a densely populated area downstream, where agricultural fields are irrigated with water with a pH between 2.5 and 3.5. The chemistry of the river water seemed to have changed over the past decade and the negative effect in the irrigation area increased. A multidisciplinary approach was used to investigate the altered situation and to get insight in the water chemistry and the hydrological processes influencing these alterations. Moreover, a first investigation of the effects of the low pH on ecosystem health and human health was performed. Water samples were taken at different sites along the river and in the irrigation area. Sampling for macroinvertebrates was performed at the same sites. Samples of soil and crop were taken in the irrigation area. All samples were analysed for metals (using ICP-AES) and other elements, and concentrations were compared to local and international standards. The river carries a very high load of SO4, NH4, PO4, Cl, F, Fe, Cu, Pb, Zn, Al and other potentially toxic elements. Precipitation and discharge data over the period of 1980-2000 clearly show that the precipitation on the Ijen plateau influences water chemistry of the downstream river. Metal concentrations in the river water exceed the concentrations mentioned in Indonesian and international quality guidelines, even in the downstream river and the irrigation area. Some metal concentrations are extremely high, especially iron (up to 1,600 mg/l) and aluminium (up to 3,000 mg/l). The food-webs in the acidic parts of the river are highly underdeveloped. No invertebrates were present in the extremely acidic water and, at pH 2.3, only chironomids were found. This also holds true for the river water with pH 3.3 in the downstream area. Agricultural soils in the irrigation area have a pH of 3.9 compared to a pH of 7.0 for soils irrigated with neutral water. Decreased yields of cultivated crops are probably caused by the use of Al containing acidic irrigation water. Increased levels of metals (especially Cd, Co, Ni and Mn) are found in different foodstuffs, but still remain within acceptable ranges. Considering local residents' diets, Cd levels may lead to an increased risk for the human health. Fluoride exposure is of highest concern, with levels in drinking water exceeding guideline values and a lot of local residents suffering from dental fluorosis. CONCLUSIONS, RECOMMENDATIONS AND OUTLOOK: In short, our data indicate that the Ijen crater lake presents a serious threat to the environment as well as human health and agricultural production.

Bathymetric and geochemical investigation of Kawah Ijen Crater Lake, East Java, Indonesia

A bathymetric survey of Kawah Ijen crater lake was conducted by acoustic sounding in 1996 to compare the lake morphology with those measured in 1922, 1925 and 1938, and to calculate the present lake volume. Even though the lake experienced several hydrothermal eruptions, the maximum depth became shallower (182 m) than before (200 m), resulting in a reduced lake volume (3.0×10 7 m 3). Fifty-two major and minor constituents including rare earth elements and polythionates (PT) of the lake waters at various depths were determined by ICP-AES, ICP-MS and HPLC, respectively. These ions except for several volatile elements are taken up by lake fringe through congruent dissolution of pyroclastics of Kawah Ijen volcano. Most ions are homogeneously distributed throughout the lake, although PT showed a considerable vertical variation. Rare earth elements (REE) in the Kawah Ijen water as well as those from other hyper-acidic crater lakes show distribution patterns likely due to the three rock dissolution (preferential, congruent and residual) types, and their logarithmic concentrations linearly depend upon the pH values of the lake waters. Using the PT degradation kinetics data, production rates of PT, injection rates of SO 2 and H 2S into the lake were estimated to be 114, 86 and 30 tons/day, respectively. Also travel time of the spring water at the Banyupahit Riverhead from Kawah Ijen was estimated to be 600–1000 days through the consideration of decreasing rates of PT. Molten sulfur stocks containing Sn, Cu, Bi sulfides and Pb-barite exposed on the inner crater slope were presumed to be extinct molten sulfur pools at the former lake bottom. This was strongly supported by the barite precipitation temperature estimated through the consideration of the temperature dependence of Pb-chlorocomplex formation.

Geochemistry of the magmatic–hydrothermal system of Kawah Ijen volcano, East Java, Indonesia

Samples from Kawah Ijen crater lake, spring and fumarole discharges were collected between 1990 and 1996 for chemical and isotopic analysis. An extremely low pH (<0.3) lake contains SO4–Cl waters produced during absorption of magmatic volatiles into shallow ground water. The acidic waters dissolve the rock isochemically to produce “immature” solutions. The strong D and 18O enrichment of the lake is mainly due to enhanced evaporation at elevated temperature, but involvement of a magmatic component with heavy isotopic ratios also modifies the lake D and 18O content. The large ΔSO4–S0 (23.8–26.4‰) measured in the lake suggest that dissolved SO4 forms during disproportionation of magmatic SO2 in the hydrothermal conduit at temperatures of 250∼280°C. The lake δ18OSO4 and δ18OH2O values may reflect equilibration during subsurface circulation of the water at temperatures near 150°C. Significant variations in the lake's bulk composition from 1990 to 1996 were not detected. However, we interpret a change in the distribution and concentration of polythionate species in 1996 as a result of increased SO2-rich gas input to the lake system.Thermal springs at Kawah Ijen consist of acidic SO4–Cl waters on the lakeshore and neutral pH HCO3–SO4–Cl–Na waters in Blawan village, 17km from the crater. The cation contents of these discharges are diluted compared to the crater lake but still do not represent equilibrium with the rock. The SO4/Cl ratios and water and sulfur isotopic compositions support the idea that these springs are mixtures of summit acidic SO4–Cl water and ground water.The lakeshore fumarole discharges (T=170∼245°C) have both a magmatic and a hydrothermal component and are supersaturated with respect to elemental sulfur. The apparent equilibrium temperature of the gas is ∼260°C. The proportions of the oxidized, SO2-dominated magmatic vapor and of the reduced, H2S-dominated hydrothermal vapor in the fumaroles varied between 1979 and 1996. This may be the result of interaction of SO2-bearing magmatic vapors with the summit acidic hydrothermal reservoir. This idea is supported by the lower H2S/SO2 ratio deduced for the gas producing the SO4–Cl reservoir feeding the lake compared with that observed in the subaerial gas discharges. The condensing gas may have equilibrated in a liquid–vapor zone at about 350°C.Elemental sulfur occurs in the crater lake environment as banded sediments exposed on the lakeshore and as a subaqueous molten body on the crater floor. The sediments were precipitated in the past during inorganic oxidation of H2S in the lake water. This process was not continuous, but was interrupted by periods of massive silica (poorly crystallized) precipitation, similar to the present-day lake conditions. We suggest that the factor controlling the type of deposition is related to whether H2S- or silica-rich volcanic discharges enter the lake. This could depend on the efficiency with which the lake water circulates in the hydrothermal cell beneath the crater. Quenched liquid sulfur products show δ34S values similar to those found in the banded deposits, suggesting that the subaqueous molten body simply consists of melted sediments previously accumulated at the lake bottom.