Albedo is a key variable in the response of glaciers to climate. In Iceland, large albedo variations in the ice caps may be caused by the deposition of volcanic ash (tephra). Sparse in situ field measurements are insufficient to characterize the spatial variation of albedo over the ice caps. Here we evaluate the latest MCD43 MODIS albedo product (collection 6) to monitor albedo over the Icelandic ice caps using albedo from ten automatic weather stations in Vatnajökull and Langjökull as ground truth. We examine the influence of the albedo variability within MODIS pixels by comparing the results with a collection of Landsat scenes. The results indicate a good ability of the MODIS product to characterize the seasonal and interannual albedo changes with correlation coefficients ranging from 0.47 to 0.90 (median 0.84) and a small bias ranging from -0.07 to 0.09. The root-mean square errors (RMSE) ranging from 0.08 and 0.21, is larger than that from previous studies, but we did not discard the retrievals flagged as bad quality to maximize the amount of observations given the frequent cloud obstruction in Iceland. We find a positive but non-significant relationship between the RMSE and the subpixel variability as indicated by the standard deviation of the Landsat albedo within the MODIS pixel (R=0.48). The summer albedo maps and time series computed from the MODIS product show that the albedo decreased significantly after the Eyjafjallajökull and Grímsvötn eruptions in 2010 and 2011 in all the main ice caps (except the northernmost Drangajökull), with albedo reduction up to 0.6 over large regions of the accumulation areas. Following this validation, these data will be assimilated in an energy and mass balance model of to better understand the relative influence of the volcanic and climate forcing to the ongoing mass losses of Icelandic ice caps.

Volcano eruptions undoubtly cause environmental impacts and damages. After the eruption, there will be vast barren land that was previously fertile ground covered by vegetation and tree line. Lava from an eruption will flow to the land via a river stream, destroying everything in its path, including vegetation. While the ecosystem actually has an ability to recover. The natural process of ecosystem recovery is related to the succession of vegetation. Then this study aims to assess and model how the ecosystem can recover and how the vegetation can respond to the damage caused by Semeru, one of the most powerful volcanic eruptions on Java island. The study areas were 2 regions that had been impacted by the Semeru lava flow for the period of 2004–2021. Based on the results, the ecosystem recovery of Semeru post-eruption was achieved within 5 years. During this time, the vegetation succession rate, as measured by vegetation cover, increased nearly ten folds. The post-eruption ecosystem recovery was indicated by the ecosystem transformation from a damaged ecosystem indicated by a lava-dominated surface to one with the presence of vegetation and hardened lava. The recovered ecosystem in Semeru's posteruption was composed of solid lava covers (39%), liquid lava (34%), and vegetation covers (27%).Then, the presence of vegetation and its succession rate can be used as a proxy of ecosystem recovery after a vast volcanic eruption.

Recently on the December 4, 2021 at 03:00 PM, 3676 m high Mount Semeru located in the East parts of Java Island has erupted. To our best knowledge, an immediate and rapid systematic analysis of the volcanic ash plume courses, PM_2.5 emissions, and environmental impacts based on Mount Semeru eruption has not been implemented so far. Then, this research aims to provide and fill the research gap on the rapid assessment of recent Mount Semeru eruption. From the result, it is clearly visible that for 12 hours the volcanic ash plume course was eastward. The volcanic ash plume can travel a distance of 0–10 km to the North and South directions, and more than 10 km to the East direction. The size of the volcanic ash plume was large at 02:00 AM on December 5, 2021. The smallest size of a volcanic ash plume was recorded at 09:00 PM on December 4, 2021. Most parts of the ash plume (55.98%) or equals 39.01 km² contain fallen volcanic material amounts ranged from 1 kg/m² to 10 kg/m². The fallen volcanic material amount peaked between 08:00 PM and 11:00 PM. Based on the estimation, the PM_2.5 content in the atmosphere increased after the eruption. The mean of PM_2.5 before the eruption was 48.5 ± 19.3(95%CI: 29.2 to 67.8 ug/m³). While after eruption the mean of PM_2.5 was 79.4 ± 32.2(95%CI: 47.2 to112 ug/m³). It indicated that the Mount Semeru eruption has increased the PM_2.5 equals 63.65%.

An eruption of volcano is related to the past volcanic and tectonic seismicity. Recently, on November 29, 2020, a 1423 m Mount Ile Lewotolok in Lembata Island has erupted. In here, this paper aimed to assess the volcanic and tectonic seismicity as determinant factor and precursor of recent Mt Ile Lewotolok eruption. The assessment shows that Mt Ile Lewotolok volcanic activities were characterized by both tectonic and deep volcanic seismicity. Since 2010, mean tectonic quake magnitudes of M 4.133 (95%CI:M 3.205-5.062) have occurred at mean depth of 13.500 km (95%CI:8.201-18.799 km) within a distance of 3-4 km from the summit. Tectonic quake has occurred frequently in southwest of Ile Lewotolok and this has contributed to the past eruptions in 2012 and 2017. Recent eruption has been influenced by deep volcanic seismicity rather than local tectonic. Based on November 2020 record, mean of deep volcanic seismicity frequency was 2.190 events/day (95%CI:1.136-3.243 events/day km) that has outnumbered (t_test=2.665, P=0.013) the events of local tectonic quakes (mean 0.621 events/day; 95%CI:0.142-1.099events/day). Prior to the eruption there was significant increase of deep volcanic seismicity (P=0.023) while local tectonic quake was not showing an increasing trend (P=0.764). This result confirms that the deep volcanic seismicity frequency is a precursor that may trigger the eruption and deep volcanic seismicity data can be used as indicator of volcanic activities.

The 1783-1784 Laki eruption was one of the most severe natural catastrophes to occur in Iceland in historical times (since 1140 years). Vegetation damage by sulphate aerosol and fluorine poisoning caused a massive decimation of livestock. The impact of fluorine poisoning and sulphate aerosol on human mortality is uncertain, but the loss of animals caused a famine which took many lives. The vulnerability of the Icelandic society to famine is discussed. 18th Century Iceland was a Danish dependency and, despite the abundance of fish in the surrounding waters, a subsistence farming community and thus highly dependent on livestock. On the other hand, the farming community possessed coping strategies which mitigated the impact of livestock loss. During the famine, the Danish government was in principle willing to provide relief. However, local authorities in Iceland were slow to ask for help, and did not dare to exploit the means at their disposal (e.g. the right to ban the export of Icelandic foodstuff) without consent from Copenhagen. The Danish officials in turn were unwilling to act decisively upon incomplete information. These two factors prevented timely measures. While 4.4 × 10^5kg of grain were provided for famine relief in summer 1784, the merchants exported 1.2 × 10^6kg of fish, which greatly aggravated the hunger in the second winter. The effects of this ‘natural’ catastrophe could therefore have been significantly reduced by efficient government.

Mount Semeru is one of the most active volcanoes in the Java Island. This article presents the results of observations and detections of volcanic ash cloud after Mt Semeru eruptions on 1 December 2020 at 01:23 AM. Volcanic ash cloud detection was conducted by analyzing thermal infrared (TIR) satellite images acquired by the NOAA-20 and SNPP with MODIS and VIIRS instruments. The TIR instruments have detected the presence of volcanic ash cloud. The results show increasing ash cloud brightness temperature (BT) from 240 to 270 Kelvin (K) several hours after eruptions. Increasing BT indicated the development of volcanic Cumulonimbus (Cb) at lower altitude. Northeast movements of 270 K BT clouds were observed at 06:12 AM. Presences of volcanic Cb and SO₂ were confirmed using IR bands of 12.0-10.8 µm, 11.0-8.5µm and 11.0 µm. This Cb cloud was observed moving northeast directions. The data acquired from the TIR imagery resulted from this study is thought be used in future to support and complement ground-based observations and detections of active volcanoes mainly in Java Island.

Tooth bud removal called Ibyinyo is the practice of removing the developing tooth buds, usually done on an infant, typically performed by traditional healers who believe that this practice will reduce fever and diarrhea in children. This practice is most prevalent in East-African countries, including Rwanda. These procedures are mostly performed in non-sterile conditions using basic sharp instruments. We will discuss the case of a 10-year-old female patient who was presented at the dental clinic, with two malformed permanent canine teeth. Clinical examination revealed malformed enamel and elongated permanent right maxillary canine tooth left mandibular canine tooth with crown malformation. She was also presented with retained (primary) left maxillary lateral incisor tooth and missing left maxillary canine tooth. In addition, the ectopic eruption of left maxillary central incisor tooth and missing permanent right mandibular canine tooth were noted. All these complications resulted from tooth bud removal that the patient had experienced in her early childhood. Her malformed right maxillary and left lower mandibular canine teeth were reshaped, using composite filling materials, to improve her appearance aesthetically. Ibyinyo is preventable damage, done out of ignorance and superstitious practices that can be stopped by growing social awareness. Therefore, educating parents through community-based campaigns on the detrimental consequences of early childhood tooth bud removal through Ibyinyo practice might be helpful to eradicate this harmful and unnecessary practice.

Primary failure of eruption (PFE) is a rare non-syndromic condition involving total or partial non-eruption of posterior teeth, in the absence of mechanical obstruction. This paper presents the case of a healthy girl referred at age 4 years for asymmetry of upper arch. Clinical examination confirmed a slight shift of the upper midline to the left, with no erupted teeth distal to the upper left canine and left posterior open bite. Panoramic X-ray showed delayed intra-osseous development of lateral left upper teeth compared to the right side. Clinic and radiographic follow-up during the next 9 years showed that 26 has not erupted by almost 13 years of age, 27 has delayed development and an unusual shape and there is agenesis of 24, 25. Genetic analysis using the PTH1R single gene sequencing did not detect any known disease-causing or rare pathogenic variants that could explain the patient's phenotype. Even when detected early, PFE rises difficult problems with regard to diagnosis and ortho-surgical treatment planning due to the impossibility to accurately predict the evolution. Tooth agenesis on the same arch worsens the prognosis and adds challenges to planning the treatment. Close long-term follow-up and timely adjustment of treatment plan in accordance to the evolution of the case are needed.

On 19 September 2021, La Palma volcano (Canarias Archipelagos) started an eruption that persisted until 13 December 2021. Despite the Volcano Explosive Index (VEI) being estimated equal to 3, corresponding to not so powerful eruption, the long eruption activity posed much scientific in-terest in this natural hazard event. In this paper, we searched for possible effects of this eruption on the atmosphere and ionosphere, investigating the climatological archive and Swarm magnetic satellite data. In particular, we explored Aerosol, Sulphur Dioxide and Carbon Monoxide con-centrations in the atmosphere identifying both the direct emissions from the volcano as well as the plume that drifted toward West-South-West and was reinforced during the eruption period. The vertical profile of temperature from the Saber satellite was analysed to search for the possible presence of acoustic gravity waves induced by volcanic activity. Compared with the year before without eruption in the areas, a lot of Saber profiles present an Energy Potential very much higher than the previous year, proposing the presence of Acoustic Gravity Waves (AGW) induced by volcano eruption activity. We also identified Swarm magnetic disturbances on the day of the eruption and in November. The mechanism of coupling could be different for the latter one, as there is no evidence for AGW. They may be due to a more complex of physical and chemical al-terations that propagate from the lower atmosphere to the upper one into the ionosphere.

This study aims to find a communication model of contingency plan for disaster risk management of Sinabung Volcano eruption, in North Sumatera. The object of the research is communication and coordination across the government, non-government organization, and community. This study used planning theory, the concept of communication planning, and types of disaster management plan as tools for analysing. Descriptive qualitative is used as the method. Data collection was obtained from the focus group discussion (FGD), in-depth interviews, observation, and study documentation. There are three stages in descriptive qualitative research that is data reduction, data presentation, and conclusion. An analysis was conducted qualitatively on the program and competence actors. The results found the communication model of disaster risk management through documents of contingency planning to overcome the threat of Mount Sinabung eruption. During the emergency response period a core model was used to reduce the impact of the Mount Sinabung eruption. The contingency plan becomes the Karo District Government’s document. This document were authorized by an authorized official and is ready to be applied to the Emergency Response Operation Plan. Plans for emergency response operations are carried out based on information regarding damage and the need to obtain results of a quick review. Contingency plans are submitted to the legislature for political commitment and support and budget allocation.

This paper presents a new methodology that provides the analysis of surface texture changes in areas adjacent to the volcano and its impact product of volcanic activity. To do this, algorithms from digital image processing such as the co-occurrence matrix and the wavelet transform are used. These methods are working on images taken by the Landsat satellite platform sensor 5 TM and Landsat 7 ETM + sensor, and implemented with the purpose of evaluating superficial changes that can warn of surface movements of the volcano. The results were evaluated by similarity metrics for grayscale images, and validated in two different scenarios that have the same type of eruption, but differ, essentially, in climate and vegetation. Finally, the proposed algorithm is presented, setting the parameters and constraints for implementation and use.

Fogo (Fogo island, Cape Verde Republic) is the youngest and most active volcano of the archipelago. The last eruption occurred in 2014–2015. Aiming at studying dust emissions and transport during the eruption period and assessing their impact on air quality and human health, a mineralogical and chemical characterization was undertaken in outdoor dust from all over the island, as well as in the lava resulting from this event. Air quality monitors were used to obtain concentrations of atmospheric particulate matter (PM) and gaseous pollutants. The mineralogical constitution of the samples was analysed by X-ray diffraction and Electron Microprobe, while the chemical characterization was performed through X-ray Fluorescence Spectrometry and ICP-MS. The volcanic rock was found to be tephritic to basanitic, with high potassium content. Several minerals were identified, such as titanian augite with ilmenite, basaltic hornblendes, pyrrhotites, apatites, pyroxenes, basaltic hornblendes and hematites. Concentrations of the particulate matter inhalable fraction (PM10) exceeded the 24-hour mean of 50 µg/m3 recommended by the World Health Organization. Nevertheless, total volatile organic compounds (TVOCs) showed levels lower than the worrying range. The highest levels of CO2 were recorded in more populated villages and farthest from the volcano. The Pollution Load Index (PLI) for outdoor dust collected on rooftops was always above 1, suggesting enrichment, with higher values in the dust size fraction < 63 µm. In the same way, the Contamination Factor pointed to high enrichment of As, Ni and Pb, and very high enrichment of Cd in the same size fraction. The Non-carcinogenic Hazard Quotient and Hazard Index estimated for Children suggest that health problems may arise. The Carcinogenic Risk, for all size fractions, was above the target risk. The element that most contributed to the global risk was As, followed by Pb and Co. Ingestion was the main exposure route for all size fractions. The dust size fraction that represented the highest risk was < 63 µm, mostly due to the As concentration.

Fogo volcano erupted in 2014-15 producing an extensive lava flow field in the summit caldera that destroyed two villages, Portela and Bangaeira. The eruption started with powerful explosive activity, lava fountains, and a substantial ash column accompanying the opening of an eruptive fissure. Lava flows spreading from the base of the eruptive fissure produced three arterial lava flows. By a week after the start of the eruption, a master lava tube had already developed within the eruptive fissure and along the arterial flow. In this paper, we analyze the emplacement processes on the basis of observations carried out directly on the lava flow field, remote sensing measurements carried out with a thermal camera, SO₂ fluxes, and satellite images, in order to unravel the key factors leading to the development of lava tubes. These were responsible for the rapid expansion of lava for the ~7.9 km length of the flow field, as well as the destruction of the Portela and Bangaeira villages. The key factors leading to the development of tubes were the low topography and the steady magma supply rate along the arterial lava flow. Comparing time-averaged effusion rates (TADR) obtained from satellite and Supply Rate (SR) derived from SO₂ flux data, we estimate the amount and timing of the lava flow field endogenous growth, with the aim of developing a tool that could be used for hazard assessment and risk mitigation at this and other volcanoes.