Masaya (Nicaragua, 12.0.sup." N, 86.2.sup." W; 635 m a.s.l.) is one of the few volcanoes hosting a lava lake, today. This study has two foci: (1) discussing the state of the art of long-term SO.sub.2 ...emission flux monitoring with the example of Masaya and (2) the provision and discussion of a continuous data set on volcanic gas data with a large temporal coverage, which is a major extension of the empirical database for studies in volcanology as well as atmospheric bromine chemistry. We present time series of SO.sub.2 emission fluxes and BrO/SO2 molar ratios in the gas plume of Masaya from March 2014 to March 2020 - covering the three time periods (1) before the lava lake appearance, (2) a period of high lava lake activity (November 2015 to May 2018), and (3) after the period of high lava lake activity. For these three time periods, we report average SO.sub.2 emission fluxes of (1000±200), (1000±300), and (700±200) t d.sup.-1 and average BrO/SO2 molar ratios of (2.9±1.5)x10-5, (4.8±1.9)x10-5, and (5.5±2.6)x10-5.
A new species,
Psammitis abuliensis
sp. nov
., from Didi Abuli Mt. (Georgia, Samtskhe-Javakheti region), is described based on two male specimens. Diagnostic drawings, measurements, collecting data, ...diagnosis, and DNA barcodes are given. A new combination,
Psammitis marmoratus
(Thorell, 1875),
comb. nov.
(ex.
Xysticus
), is proposed based on the COI subunit barcode results and morphological characters.
The Unknown eruption of 1808/1809 was the second most explosive SO2-rich volcanic eruption in the last two centuries, eclipsed only by the cataclysmic VEI 7 Tambora eruption in April 1815. However, ...no eyewitness accounts of the event, and therefore its location, or the atmospheric optical effects associated with its aerosols have been documented from historical records. Here we report on two meteorological observations dating from the end of 1808 that describe phenomena we attribute to volcanic-induced atmospheric effects caused by the Unknown eruption. The observations were made by two highly respected Latin American scientists. The first, Francisco José de Caldas, describes a stratospheric aerosol haze, a "transparent cloud that obstructs the sun's brilliance", that was visible over the city of Bogotá, Colombia, from 11 December 1808 to at least mid-February 1809. The second, made by physician José Hipólito Unanue in Lima, Peru, describes sunset after-glows (akin to well-documented examples known to be caused by stratospheric volcanic aerosols) from mid-December 1808 to February 1809. These two accounts provide direct evidence of a persistent stratospheric aerosol veil that spanned at least 2600 km into both Northern and Southern Hemispheres and establish that the source was a tropical volcano. Moreover, these observations confirm that the Unknown eruption, previously identified and tentatively assigned to February 1809 (±4 months) from analysis of ice core sulfate records, occurred in late November or early December 1808 (4 December 1808 ±7 days). This date has important implications for the associated hemispheric climate impacts and temporal pattern of aerosol dispersal.
Volcano Observation - Now and Future SHIMADA, Masanobu
Journal of The Remote Sensing Society of Japan,
2021/05/15, Letnik:
41, Številka:
2
Journal Article
Vegetation research on the lava flows of the historic volcanic eruption of 1705 in Arafo, Tenerife, Canary Islands, is presented. The study area located in the 830000-year-old valley of Guimar was ...created after a massive landaslide 47 km.sup.3 in volume. The research is divided into three parts, which cover an altitudinal range from around 35 to 1583 m asl from the Lower-semiarid Inframediterranean up to the Lower-dry lower-Mesomediterranean bioclimatic belts. First, a phytosociological study of the vegetation present in the area was made and concluded that richness in pioneer communities form a vegetation complex with a high degree of endemicity. Two new associations and four pioneer communities are proposed. Especially notable are the communities of Stereocauletum vesuviani and the pioneer communities of Pinus canariensis. The second part of the research was a field sampling study of 450 individuals of Pinus canariensis, which were measured at different altitudes to obtain data about the colonization dynamics of this species on this 300 years old substrate. We found that stem diameter seems to be a good indicator for healthy tree development at a range between 700 to 1300 m asl, which corresponds to the pine forest as potential vegetation and that many individuals show signs of nutrient deficiency. The third part consists of the publication of two new populations of the Canarian endemism Himantoglossum metlesicsianum, a highly endangered orchid. The monitoring of these two populations has recently begun, and further research will be conducted on all three aspects of this publication, which will be presented and expanded upon in the future.
The eruption of the Hunga Tonga‐Hunga Ha'apai Volcano in January 2022 in the southwest Pacific islands of Tonga triggered a tsunami that was detected beyond the Pacific basin. Here we show its ...spatiotemporal signature as revealed by hundreds of publicly available coastal tide gauge records from around the world. The Tonga tsunami was characterized by a uniformly small leading wave that arrived earlier than theoretically expected for a tsunami wave freely propagating away from the volcano. In contrast, the largest waves, of up to +3 m high, were concentrated in the Pacific and their timing agrees well with tsunami propagation times from the volcano. While the leading waves were caused by a previously reported fast‐moving atmospheric pressure pulse generated in the volcanic explosion, the large waves observed later in the Pacific were likely originated in the vicinity of the volcano although its generation mechanism(s) cannot be identified by the tide gauge data alone.
Plain Language Summary
In January 2022, a submarine volcano in the southwest Pacific islands of Tonga erupted and triggered a tsunami that was detected at many places, even outside the Pacific Ocean. The Tonga tsunami was recorded by hundreds of coastal stations that continuously measure the sea level around the world. Here, we analyze such records to provide a global picture of this tsunami. We found that the up and down movements of the sea surface (tsunami waves) around the Pacific coast were distinctly different than those at other parts of the world. The Pacific measurements feature small tsunami waves before the occurrence of much larger waves. Outside the pacific we mainly see these small first waves that do not grow too much afterward. Because the timing of these first waves coincides with the passing of a previously reported atmospheric pressure wave generated in the volcanic explosion, we think they were caused by interactions between the air and seawater. This is why we also see them outside the Pacific. In turn, the much larger waves at the Pacific were likely originated in the vicinity of the volcano. This is why we do not see them elsewhere.
Key Points
Analysis of 589 tide gauge records reveals the spatiotemporal features of the 2022 Tonga volcanic tsunami around the world oceans and seas
The leading wave was ubiquitously small, and its early arrival suggests it was caused by a moving air pressure wave produced in the explosion
The largest waves were concentrated in the Pacific with occurrence times consistent with an origin in the vicinity of the volcano
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