Distribution Characteristics of the Introduced Non-Native Toad Bufo formosus 20 Years after a Volcanic Eruption on Miyake-Jima Island

The populations of red alga Gelidium elegans along the coast of Miyakejima Island were severely damaged by a volcanic eruption in 2000. The effect of this volcanic eruption has been long lasting, and populations of this red alga still have not recovered. We investigated the effect of seabed sediment particles derived from volcanic ash on the substrate adhesion of G. elegans spores. The analysis provides evidence that increasing amounts of sediment particles result in lower adhesion rates of G. elegans spores, and that smaller sediment particles have a greater influence on adhesion. The amount of seabed sediment particles around Miyakejima Island was 9.3–1815.4 mg/cm2. This amount has changed greatly from year to year. The adhesion rate of G. elegans spores in water around Miyakejima Island was 0 % at all points in 2008 and 2010, but it was estimated as 6.3–38.6 % in 2009. These results suggest that there is significant inhibition of algal spore adhesion by seabed sediment particles derived from volcanic ash around Miyakejima Island.

Volcanic eruptions can have significant impacts on plant and animal communities. Thus, it is important to understand the recovery process following these eruptions, particularly on isolated islands, in order to assist with biodiversity management and conservation. We studied relationships between vegetation structure and avian species composition on Miyakejima Island, Japan, where a volcanic eruption in 2000 destroyed almost half of the vegetated land. Bird species and nine vegetation variables were surveyed at 24 sampling sites from 2011 to 2014. The results showed that avian species composition mainly varied along two vegetation variables, namely plant species richness and total basal area of all tree species. Bird species were classified into four groups, that is, grassland species, widely distributed species, developing-forest species, and developed-forest species. Developed-forest species were only recorded at the sites where vegetation height was more than 10 m. The relationship between developed-forest bird abundance and vegetation height was similar to that between total basal area of all tree species and vegetation height. The restoration of mature evergreen forest is essential to conserve avian diversity on the island, and natural seed dispersal by birds plays an important role in supporting forest restoration after a major disturbance.

The vegetation of Miyake Island has been widely effected by the volcanic eruption in July 2000. This phenomenon is still going on and much of the vegetation cover has been changed. It is quite important to monitor the vegetation recovery process because of ecosystem study, prevention of disaster and rehabilitation of the Island. This study investigated an evaluation of the vegetation recovery process in Miyakejima Island after the 2000 volcanic eruption using satellite remote sensing and field vegetation survey. Multi temporal 12 satellite images of Terra/ASTER and JERS-1/OPS were selected and combined into three time series datasets such as the before eruption, the after eruption within two years and the after eruption more than three years. These three time series image datasets were analyzed into the seamless images of the maximum NDVI value. According to the unsupervised classification of these three images, Miyakejima Island was divided into six classes with vegetation change patterns. These results followed past works and field vegetation survey well. The classes were recognized with the vegetation change which shows the damage of trees and the recovery of vegetation after the volcanic eruption of the year 2000.

Rehabilitation from the long-term evacuations by disasters, Volcanic eruptions on Miyakejima Island and 311 disaster on "Fukushima"

The bare lands formed after volcanic eruptions provide an excellent opportunity to study the interactions between vegetation succession and soil formation. To explore the changes in soil physicochemical properties in the vegetation succession processes and the relationship between them, soil physicochemical properties of different volcanic ash accumulation on Miyake-jima Island were studied at different vegetation succession stages. The results showed that soil bulk density gradually decreased and that soil porosity, soil water content (SWC), pH, cation exchange capacity (CEC), soil total organic carbon (TOC), and total nitrogen (TN) increased significantly with vegetation succession. The physicochemical properties changes in the soil surface horizon were most obvious, and the deep soil accumulated a large amount of relatively stable soil carbon and nitrogen. The forest land formed a thicker organic matter horizon, accumulating more carbon and nitrogen than grassland, and the soil quality index (SQI) was higher than that of grassland and shrubland. In conclusion, our research indicates the significant change in soil physicochemical properties and the improvement in soil quality in the vegetation succession processes, emphasizing a significant relationship between vegetation succession and soil development in bare land.

Monitoring natural disasters through multiple satellite data

In this study, the role of AD 1258 Samalas mega volcanic eruption in the summer hydroclimate change over Europe and the corresponding mechanisms are investigated through multi-member ensemble climate simulation experiments based on the Community Earth System Model (CESM). The results show that the CESM simulations are consistent with the reconstructed Palmer Drought Severity Index (PDSI) and the historical records of European climate. Europe experiences significant summer cooling in the first three years after the Samalas mega volcanic eruption, peaking at −3.61 °C, −4.02 °C, and −3.21 °C in year 1 over the whole Europe, Southern Europe, and Northern Europe, respectively. The summer surface air temperature (SAT, °C) changes over the European continent are mainly due to the direct weakening of shortwave solar radiation induced by volcanic aerosol. The summer precipitation over the European continent shows an obvious dipole distribution characteristic of north-south reverse phase. The precipitation increases up to 0.42 mm/d in year 1 over Southern Europe, while it decreases by −0.28 mm/d in year 1 over Northern Europe, respectively. Both simulations and reconstructions show that the centers with the strongest increase in precipitation have always been located in the Balkans and Apennine peninsulas along the Mediterranean coast over Southern Europe, and the centers with the strongest precipitation reduction are mainly located in the British Isles and Scandinavia over northwestern Europe. The negative response of North Atlantic Oscillation (NAO) with significant positive sea level pressure (SLP) anomaly in the north and negative SLP anomaly in the south is excited in summer. The low tropospheric wind anomaly caused by the negative phase of NAO in summer affects the water vapor transport to Europe, resulting in the distribution pattern of summer precipitation in Europe, which is drying in the north and wetting in the south. The knowledge gained from this study is crucial to better understand and predict the potential impacts of single mega volcanic eruption on the future summer hydroclimate change in Europe.

The development of continental rift basins is often accompanied by multiple episodes of volcanic activity. The impact of these volcanic eruptions on the sedimentary filling process of the basin is a geological problem worth considering. This relationship is not only the premise for reasonably explaining the binary filling characteristics and development of sequences of volcanic rocks and sedimentary rocks in rift basins but also the key geological basis for the prediction of volcanic and sedimentary rock reservoirs in rift basins. On the basis of a large amount of three-dimensional seismic data, logging data and lithology data, we estimated the volcanic eruption period, volcanic rock mass and spatial shape of the Changling faulted depression in the Songliao Basin. We then studied the spatial distribution characteristics of lithofacies and sedimentary facies in the basin. Finally, we assessed the influence of volcanic eruptions on the type of sedimentary filling, the distribution of sedimentary facies and the spatial stacking of sedimentary strata. This study revealed that during the rapid rifting stage (Yingcheng Formation depositional period), the Changling faulted depression developed mainly fan delta, braided river delta and lacustrine sedimentary systems and experienced four phases of volcanic eruptions. The lithology, scale and spatial distribution of volcanoes were directly related to the activity and location of the basement faults in this area, reflecting the control that basement fault activity had on the volcanic eruptions. Moreover, the stacking form and eruption scale of volcanic rocks played a substantial role in the paleogeomorphology of the basin, which in turn affected the form of the source channel of the basin, causing changes in the sedimentary facies type and spatial distribution and changes in the spatial overlapping pattern of the sedimentary sequence. Moreover, volcanic eruptions provided different sources of debris to the continental lake basin. The differences in location and delivery methods of these materials complicate the rock structure and reservoir properties of the basin sandstone.

The advancement of remote sensing technology has contributed to a significant level of assistance in reducing nature's calamities, threatening both human lives and property in its immediate vicinity. Volcanic eruption is one of a kind where the dangerous environment surrounding it also causes great difficulties for close-up monitoring and surveillance. Differential Synthetic Aperture Radar Interferometry (DInSAR) is a technique useful for accurately detecting the ground displacement or land deformation in the antenna line-of-sight (slant-range) direction using synthetic aperture radar (SAR) data taken at two separate acquisitions. As one of important targets of the DInSAR analysis, we have studied the volcanic eruption of Miyakejima island, successfully demonstrating the detection of land deformation around its crater.

Tephra from volcanic eruptions contains only small amounts of mercury (Hg) right after the eruption because the high temperature at eruption evaporates Hg in volcanic ash. Thus, accumulation of Hg in tephra soil layers during the dormant periods of the volcano may reflect Hg deposition while the layer was exposed to the atmosphere. To estimate sequential changes in Hg deposition, we measured the Hg content and accumulation in tephra layers from 6 sites in Hokkaido known to have many tephra layers derived from volcanic eruptions over a 34,000-year period. Mercury content and accumulation rate in the soil profiles varied widely depending on the tephra. In each tephra layer, the Hg content and accumulation rates increased principally at the upper soil horizons and decreased at the lower depths. The Hg deposition rates calculated from the amount of Hg accumulated in the tephra layers were similar within the same tephra. These characteristics of Hg distribution indicate that Hg deposition accumulated on the surface of each tephra layer during the period the tephra layer was exposed to the atmosphere. Although physicochemical processes such as leaching out, wind erosion, and volatilization might lead to over- and/or underestimation of the deposition rates, our estimated amounts of Hg were markedly higher in the tephra soils after 1,600 year BP than before that time. The results of this study suggest that tephra layers in Hokkaido offer important implications for understanding of the historical changes in atmospheric Hg deposition.

    Existing literature indicates that volcanic lightning occurs during a devastating volcano eruption. However, it is still limited to understanding the volcanic electrification mechanism in nature because of the rarity of the explosive volcano eruption and visible spectrum obstacles from plumes full of dirty ashes. The eruption of the Hunga Tonga–Hunga Haʻapai (HT-HH) submarine volcanoes in the Lau Basin, South Pacific, had an extremely violate surtseyan type eruption on January 15th and generated numerous volcanic lightning. This eruption event provides a great opportunity to explore the electrification and evolution of volcanic lightning.     In this work, more than 40,000 lightning events were detected by the World Wide Lightning Location Network (WWLLN) during the primary eruption on January 15th. At the first stage of the eruption, the geographic distribution of lightning strikes expanded rapidly and isotropically while the eruption column reached a specific altitude. Then a lightning tranquility period occurred subsequently, implying explosive erupting was intermittent. Several explosive sub-eruptions were detected from 04:00Z to 07:00Z, and sub-eruptions' timestamps are highly consistent with seismic data analysis from IRIS. Lightning footprint provided evidence that the HT-HH eruption was a surtseyan eruption unsteady with several quiescent phases separating the explosive stages.    HT-HH is one of the most powerful eruptions of the 21st century and provides a favorable environment for volcanic lightning research. The result of this work can track the immediate eruption by using lightning activities. Moreover, volcanic lightning has a different charging mechanism than general tropospheric lightning. Therefore, many interesting issues can be discussed, such as the volcano eruption's contribution to global electrical circuits or whether volcanic lightning can generate other atmospheric electricity events like TLEs or TGFs.

OBJECTIVE To study the differences between clinically amyopathic dermatomyositis (CADM) and typical dermatomyositis (DM) on clinical and immunological features. METHODS By collecting clinical data of 106 CADM patients and 158 DM patients from January 2010 to June 2019 in the department of Rheumatology and Immunology, Peking University People's Hospital, the clinical characteristics and immunological features in the two groups were compared, and the distribution characters and the clinical meanings of myositis autoantibodies were discussed in the two groups respectively. Myositis autoantibodies were measured by immunoblotting according to the manufacturers' instructions. RESULTS In the aspects of clinical manifestations, CADM presented more with onset of interstial lung diseases (ILD) compared with DM (20.7% vs. 7.6%, P=0.002), and CADM-ILD was more likely to be acute ILD (58.3% vs. 26%, P < 0.001), and there were no differences between CADM and DM in cutaneous manifestations, accompanied with connective tissue disease (CTD) and malignancy. In CADM, the positive rate of rheumatoid factors and antinuclear antibodies was lower in DM. The most common myositis specific autoantibodies (MSAs) in CADM were anti-MDA5 (36%), anti-PL-7 (11.2%) and anti-TIF-1γ (10.1%). The most common MSAs in DM were anti-Jo-1 (19.2%), anti-TIF-1γ (11.5%) and anti-MDA5 (11.5%). Anti-MDA5 was correlated with acute ILD and skin ulceration both in CADM and DM; in CADM, skin ulceration was not associated with the titer of anti-MDA5; while in DM, skin ulceration was associated with high titer of anti-MDA5. In DM, anti-TIF-1γ was correlated with heliotrope eruption, V/shawl neck sign, perionychia erythma and malignancy, and higher rate of malignancy was seen in all titers of the anti-TIF-1γ positive patients. In CADM, anti-TIF1-γ showed no correlation with clinical manifestations. The most common myositis associated autoantibody was anti-Ro-52 both in CADM and DM. In CADM, anti-Ro-52 was associated with Raynaud's phenomenon and chronic ILD, while in DM, anti-Ro-52 was associated with mechanic's hands, noninfectious fever and accompanied CTD. CONCLUSION Compared with DM, ILD is more likely to be acute in CADM. It is different between CADM and DM about the distribution of myositis autoantibodies and the clinical significance of the same myositis antibody, and the clinical significance of some myositis antibodies is related to titers.

Using Magellan Seamount samples in the Pacific area to carry out the REE chemical analysis and microscopic descript,this paper analyze the content of REE between the basement rock and co-rich crust, distribution characteristics, distribution pattern.The results show that: the three layers samples contain high value, total quantity is about 1000×10-6, compared with normal deep sea sediments, foraminiferal nuclear shell and sea water content of rare earth elements10 ~ 100 times; Basement and co-rich crust have shown consistent in distrubution mode, REE content is perfectly high, co-rich crust of REE is mainly controlled by overlying seawater on the rock points erosion. volcanic eruption, ocean floor basalt weathering and biological chemical deposition on the formation of the crust also has certain influence. REE as a huge resource is superior to exploit, The comprehensive development and utilization of mineral resources provided good premise, it is possible to createREE resource utilization of the new way.

Tsunami monitoring and early warning systems are mainly established to deal with seismogenic tsunamis generated by sudden seafloor fault displacement. However, a global tsunami triggered by the 2022 Tonga volcanic eruption promoted the need for tsunami early warning and hazard mitigation of non-seismogenic tsunamis in coastal countries. This paper studied the spatiotemporal distribution characteristics of historical volcanic tsunamis and summarized high-risk areas of volcanic tsunamis. The circum southwestern Pacific volcanic zone, including the Sunda volcanic belt and the Indo-Australian plate, is a concentrated area of active volcanoes and major volcanic tsunamis. In addition, the challenges associated with adapting seismogenic tsunami techniques for use in the context of volcanic tsunamis were elucidated. At the same time, based on historical records and post-disaster surveys, typical historical volcanic tsunami events and involved mechanisms were summarized. The results show that a majority of volcanic tsunamis may involve multiple generation mechanisms, and some mechanisms show geographical distribution characteristics. The complexity of volcanic tsunami mechanisms poses challenges to tsunami early warning by measuring tsunami sources to evaluate the possible extent of impact, or using numerical modeling to simulate the process of a tsunami. Therefore, a concise overview of the lessons learned and the current status of early warning systems for volcanic tsunamis was provided. Finally, a conceptual scheme of monitoring systems for volcanic tsunamis based on historical volcanoes, real-time volcanic eruption information and sea level data, as well as remote sensing images, was presented.

Characteristics of Time-Space Distribution on the Occurrence of Earthquakes and Volcanic Eruptions in and around East Japan Island Arcs