Effects Of Volcanic Activity Research Articles

The Impacts of Volcanic Activity on Microbial Growth—A Simulation Experiment in the Qiliao Section in Shizhu County, Chongqing, China

The impact of volcanic activity on microorganisms has always been a hot topic of discussion during geological history. Further studies are needed on the effects of volcanic activity on microbial growth in shale and the differences in nutrients provided by volcanic ash and other weathered rocks. This study’s results indicated that TOC contents at the bottom of the shale layer are 1.93–4.44% and 3.0% on average. The TOC contents at the top of the layer are 3.38–5.13% and 4.0% on average. It indicated that TOC contents at the bottom of the shale layer are smaller than the TOC contents at the top of the layer, suggesting that volcanic activity posed a long-term effect on biological growth. Seven different leachate concentrations were set in this experiment as follows: 1/10, 1/100, 1/500, 1/1000, 1/1500, 1/2000, and 1/2500. The results showed that the growth status of Pseudourostyla crassipes was affected by the addition of leachates with different concentrations compared to the control group. Additionally, the synthesis of chlorophyll a by Anabaena pseudoichthyoides was the most efficient with the 1/10 volcanic ash leachate. Through the analysis of major and trace elements in the solution before labeland after cultivation, the main elemental content of Ca2+, Mg2+, Na+, and K+ decreased by 3.8~87.24%, 75.96~92.70%, 86.56~95.67%, and 5.42~20.52% in the solution after microbial growth respectively. The trace elements B, Ba, Zn, and Fe decreased by 27.54~94.39%, 20~82.03%, 70.45~98.29%, and 99%. It was found that the B, Ba, Fe, and Zn elements decreased significantly. The nutrients from volcanic ash are the main factor promoting microbial growth. It can be indicated that the volcanic ash soaking solution has a higher content of nutrients when compared to the solubility of nutrients in volcanic ash compared to that of granite. A higher content of nutrients promotes microbial growth. The calculation results indicate that a volcanic eruption with a quantity of several 1010 m3 has a significant impact on microorganisms, lasting from tens of thousands to hundreds of thousands of years.

Effects of Volcanic Activity on Organic Matter Sources and the Paleoenvironment: Geochemical Evidence from Upper Carboniferous Source Rocks (Batamayineishan Formation) in Eastern Junggar, NW China

Effects of Volcanic Activity on Organic Matter Sources and the Paleoenvironment: Geochemical Evidence from Upper Carboniferous Source Rocks (Batamayineishan Formation) in Eastern Junggar, NW China

Effects of Volcanic Activity on Organic Matter Enrichment in the Sediments and its Implications for Oil and Gas Exploration and Development

Volcanic activity is an important geological phenomenon in the evolution and development of the earth and brings rich resources to benefit human society, such as geothermal resources, valuable minerals, petroleum, and natural gas, although volcanic eruptions cause serious threats to the ecological environment of our planet. The co-development of oil and gas and volcanic activity in the same basin is a common phenomenon globally. Volcanic activity can bring abundant nutrients into the basins, conducive to the development of algae and other microorganisms in the water body. After the death of organisms, their remaining settles down to the water bottom and accumulate in the sediments. Meanwhile, reducing gases, releasing along with the volcano eruption, including H2S, CO2, etc., result in anoxia in the water body, benefiting the preservation of organic matter at the bottom and brings a large amount of material basis for the generation of oil and gas. Additionally, volcanic activity and hydrothermal fluids are rich in acid substances, will dissolve part of the minerals in the formation, generates a large number of migration channels for oil and gas migration. Some volcanic rocks are rich in pores, making them natural tanks for oil and gas storage. However, volcanic activity also has destructive effects on oil and gas accumulation. High hydrothermal/volcanic input can dilute primary productivity or reduce the abundance of organic matter due to high deposition rates, while excessive volcanic activity or hydrothermal fluid input can introduce large amounts of sulfate into the water, causing strong bacterial sulfate reduction (BSR). The high consumption of organic matter can hamper the organic matter enrichment. Therefore, how to define appropriate volcanic activity conducive to organic carbon preservation, and to establish the relationship model between volcanic activity and organic matter enrichment, are key scientific issues.

Effect of Volcanic Activity on Hydrocarbon-Forming Organisms in Organic-Rich Shale: A Case Study of Dalong Formation in Northwestern Sichuan Basin, China

Hydrocarbon-generating material determines the elemental composition and hydrocarbon-generating potential of kerogens in a source rock, and it is the key material basis to control the hydrocarbon-generating capacity of the source rock. Previous studies have shown that many intervals of high-quality source rocks generally contain a varying number of volcanic ash layers. The impact of these volcanic ash layers on the development of high-quality source rocks has attracted extensive attention. However, these studies mainly focused on the development of hydrocarbon-forming organisms and the preservation of organic matters but rarely dealt with the differential development of hydrocarbon-forming organisms between multiple volcanic ash layers. The Permian Dalong Formation in the northwestern Sichuan Basin, China, is a set of high-quality source rocks with multiple volcanic sedimentary layers. To understand the differential development of hydrocarbon-forming organisms between volcanic ash layers, with the Dalong Formation in the Longfeng quarry section, Guangyuan, the Sichuan Basin as an example, this study analyzes the types of hydrocarbon-generating materials of high-quality source rocks of the Dalong Formation and the reasons why volcanic activities affected the growth of hydrocarbon-forming organisms and explores the impact of volcanic activities on the development of different types of hydrocarbon-forming organisms. The results show that the TOC of the Longfeng quarry section is 0.05%–15.46%, with an average of 4.76%, and the average TOC of the Dalong Formation is as high as 5.16%, which belongs to high-quality source rocks. The hydrocarbon-forming organism association in the Dalong Formation source rocks is mainly composed of floating algae and benthic algae and vertically divided into three parts: a few radiolarians and trace fossils occasionally in the lower part; a large number of radiolarians, calcium spheres, and algal debris in the middle part; and mainly foraminifera and gastropods in the upper part. There are 36 volcanic ash layers in the Dalong Formation of the study area. In the process of volcanic activity, the “fertilization” effect of volcanic ash made the nutrient elements in the volcanic ash enter water, increasing the number of hydrocarbon-forming organisms, causing the differential development of various hydrocarbon-forming organisms, and promoting the formation of reducing water to support the preservation of organic matters. The development of hydrocarbon-forming organisms is controlled by the changes of element types and abundances caused by magmatic properties. The time interval of volcanic activities also has an important impact on the development of hydrocarbon-forming organisms.

Effect of Volcanic Activity on Succession of Woody Vegetation and Water Infiltration Rates on Peripheral Slopes of Sakurajima Volcano, Japan

Effect of Volcanic Activity on Succession of Woody Vegetation and Water Infiltration Rates on Peripheral Slopes of Sakurajima Volcano, Japan

Effect of volcanic activity on hydrocarbon generation: Examples in Songliao, Qinshui, and Bohai Bay Basins in China

Numerous gas reservoirs in volcanic rocks have been found worldwide. Three gas fields with reserves of one billion cubic meters of gas related to volcanic rocks were found in China. Hence, volcanic rocks as reservoir rocks are attracting increasing attention from geologists. Volcanic activity cannot only form excellent reservoir rocks but also affect hydrocarbon generation in source rocks. The influence of volcanic rocks on the maturation of source rocks and gas generation rate in the Songliao, Qinshui and Bohai Bay Basins in China is discussed in this paper. The main effects of volcanic rocks on gas generation are as follows: Firstly, volcanic activity always leads to a high regional paleo-geothermal gradient that accelerates the thermal evolution of the source rocks. For example, although the present-day geothermal gradient is only 3.7 °C/100 m, the geothermal gradient reached up to 6.5 °C/100 m in the Songliao Basin when volcanoes were erupting on a large scale. Hence, the Cretaceous Shahezi source rocks, interbedded with two sets of volcanic rocks, had high gas generation rate and rapidly reached high-to over-mature stages (the vitrinite reflectance (Ro) is approximately 3.5% or more). The gas generation rate was 10 times higher than that of other gas-abundant basins in China, like Ordos Basin, and the gas generation intensity was up to 2.4 × 1010 m3/km2. Secondly, igneous intrusions make local source rocks reach high-to over-mature stages very quickly and generate gas promptly, even during source rock uplifting. Many areas were intruded by igneous rocks during the Jurassic to Cretaceous, for example, the paleo-geothermal gradient was as high as 5.5 °C/100 m in the Qinshui Basin. The source rocks were still generating hydrocarbons while the whole Qinshui Basin was being uplifted. The gas generated due to volcanic activity accounted for more than 70% of the total gases generated from source rocks and formed a large coal seam gas field in the Qinshui Basin. Thirdly, when source rocks developed with concomitant volcanic eruptions or igneous intrusions, these types of volcanic rocks were normally on a small scale, and therefore their areas of influence were small. Hot fluids and transition metals from volcanic activity catalyzed and accelerated the thermal evolution of the source rocks so that large amounts of low-mature hydrocarbon were generated.

Effect of Volcanic Activity on Succession of Woody Vegetation and Growth Environment, and Water Infiltration Rate on Sakurajima Volcano, Japan

Effect of Volcanic Activity on Succession of Woody Vegetation and Growth Environment, and Water Infiltration Rate on Sakurajima Volcano, Japan

Effects of volcanic activity on formation of alpine moors during Holocene

Effects of volcanic activity on formation of alpine moors during Holocene

Spring-summer droughts in the Czech Land in 1805-2012 and their forcings

Drought is an extreme meteorological phenomenon involving serious economic consequences. In the Czech Lands, it is reflected in significant reductions in agricultural productivity, lack of water for hygiene and industry, and impacts of forest management. Mean monthly temperature and precipitation series created for the Czech Lands for 1805–2012 were used to calculate spring (MAM) and summer (JJA) drought indices (SPI-1, SPI-12, SPEI-1, SPEI-12, Z-index and PDSI), which were then used for further analyses. Fluctuations in drought indices demonstrate an increasing long-term dryness in the Czech climate, statistically significant for SPEI-12 and PDSI in MAM and JJA (in MAM as well for SPEI-1 and Z-index). A significant concentration of drought episodes before 1880 may be attributed to a lack of precipitation, whereas the droughts of recent decades (particularly 2004–2012) are more strongly related to high temperatures. The effects of droughts are reflected in significant reductions in winter wheat and spring barley yields in the eastern province of Moravia. Regression analysis of drought forcings discloses the importance of the North Atlantic Oscillation phase and the aggregate effect of anthropogenic forcing (driven largely by increases in CO2 concentration). Their magnitude of influence varies strongly with the type of drought index and season of the year. Other factors, such as solar irradiation and the Southern Oscillation phase make only minor contributions to drought variability. The effects of volcanic activity and the Atlantic Multidecadal Oscillation are even weaker and statistically insignificant.

Dynamics of Piton de la Fournaise volcano observed by passive image interferometry with multiple references

Activity of Piton de la Fournaise (PdF) volcano in La Réunion Island modifies the seismic velocities within the edifice. Using the 2010 and 2011 data from a network of 21 seismic stations in the vicinity of PdF, changes of seismic velocities are investigated using passive image interferometry, i.e. interferometry of seismic noise correlations. As noise correlations change significantly over time in response to volcanic activity, a method is presented that allows us to measure continuous long term velocity changes with high and constant accuracy by using multiple periods as reference. A long term velocity increase is found that averages about 0.25% per year. This trend is superimposed by short term changes that exhibit a clear connection with summit seismo-tectonic earthquakes indicating the effect of volcanic activity. Characteristic signatures of velocity changes are identified for post-eruptive periods of deflation that show an increase of velocity associated with subsidence observed by GPS. Periods of pre-eruptive inflation are characterized by decreasing velocity. Seismic crises can be associated with either increasing or decreasing velocity depending on whether the magma movement leads to deflation due to an eruption emptying the shallow plumbing system or to inflation caused by a non-eruptive intrusion. With a simple assumption about the spatial sensitivity of the measurements both processes are found to have the strongest effect in the central summit area of the volcano which also shows the strongest surface displacements during the time investigated here. We do not observe a dependence of the velocity change on the location of the erupting fissures, instead the distribution of changes for the three inflation periods and the two eruptions are similar indicating that the velocity changes observed here reflect the dynamics of a shallow magma reservoir rather than the effect of the eruption at the surface.

Landscape structure change of Matua Island in the latter half of the 20th – beginning of the 21st centuries (Kuril Archipelago)

For the first time for the Kuril Islands, we present the results derived from investigating the changes in landscape structure of Matua Island that have been taking place since the latter half of the 20th century under the effect of volcanic activity. We constructed the 1:200 000 landscape maps for different time spans. We consider in detail the issue relating to the development of the geosystems on the island in the wake of the 2009 eruption. A cartographic-statistical analysis of the landscape maps is carried out, and the role of volcanism in the change of the quantitative parameters of landscapes is highlighted.

The influence of volcanism on paleoclimate in the northeast of China: Insights from Jinchuan peat, Jilin Province, China

Just like contemporary sediments, peat itself is a good repository of information about climate change, the effects of volcanic activity on climate change have been truly recorded in peat, since it is a major archive of volcanic eruption incidents. A section of sand was identified as tephra from the Jinchuan peat, Jilin Province, China, for the grains look like slag with surface bubbles and pits, characterized by high porosity, and loose structure with irregular edges and corners. According to the peat characteristics of uniform deposition, the tephra was dated at 2002–1976 a B.P. by way of linear interpolation, so the time of volcanic eruption was 15 B.C.–26 A.D. (the calibrated age). While the geochemical characteristics of tephra in this study are quite the same as those of tephra from the Jinlongdingzi volcano at Longgang and from alkaline basaltic magma, with the contents of SiO2 K2O. We speculated that the tephra in this study came from the Longgang volcano group. Compared with 11 recorded volcanic eruption events as shown on the carbon and oxygen isotope curves of the Jinchuan peat cellulose, it is obviously seen that adjacent or large-scale volcanic eruptions are precisely corresponding to the minimum temperature and humidity. It seems that these volcanic eruptions indeed affected the local climate, leading to the drop of regional temperature and humidity. As a result, there was prevailing a cold and dry climate there, and all these changes can be well recorded in peat. So the comparison of volcanic eruption events with information about climate change developed from peat, can provide strong evidence for the impact of volcanism on climate change.

Transport and transformation of total reactive nitrogen over the East China Sea

Ground‐based measurement of total reactive nitrogen (NOy), NOy(g) (gas phase NOx + HNO3), and particulate NO3− was carried out at the Cape Hedo Atmosphere and Aerosol Monitoring Station (CHAAMS) in Okinawa, Japan, from spring to winter in 2006. The concentrations of NOy, NOy(g), and particulate NO3− were simultaneously high in spring but low in summer. This difference was mainly caused by air mass history, which was strongly associated with the typical weather pattern observed in the east Asian region for each season. The chemical transformation process of particulate NO3− during transport was examined using the data measured at Qingdao, China, in spring 2006. As the transport time of air masses increased, particulate NO3− continuously shifted from fine mode to coarse mode. It was found that the chemical transformation of particulate NO3− was mainly associated with the transport time of air masses, the geographical position of CHAAMS, and the transition from NH4NO3 to gas phase HNO3. In air masses from Qingdao, China, the ratio of NOy concentration observed at CHAAMS to that at Qingdao was about 0.1, which was lower than that of SOy (SO2 + nss‐SO42−). Sulfate was found in fine particles at CHAAMS in contrast to particulate NO3−. As the lifetimes of NOy and SOy depend on the particle size, the difference in chemical transformation process during transport largely influences the abundance of transported NOy. The variations of NOy(g) and particulate NO3− were analyzed when dust plumes reached CHAAMS. The presence of dust causes the formation of particulate NO3− in coarse mode from NOy(g) and an increase of its fraction in NOy. The effect of volcanic activity on particulate NO3− concentration was also analyzed. It is suggested that particulate NO3− escaped to gas phase HNO3 through the uptake of abundant volcanic H2SO4 by aerosols.

Young volcanism and related hydrothermal activity at 5°S on the slow‐spreading southern Mid‐Atlantic Ridge

The effect of volcanic activity on submarine hydrothermal systems has been well documented along fast‐ and intermediate‐spreading centers but not from slow‐spreading ridges. Indeed, volcanic eruptions are expected to be rare on slow‐spreading axes. Here we report the presence of hydrothermal venting associated with extremely fresh lava flows at an elevated, apparently magmatically robust segment center on the slow‐spreading southern Mid‐Atlantic Ridge near 5°S. Three high‐temperature vent fields have been recognized so far over a strike length of less than 2 km with two fields venting phase‐separated, vapor‐type fluids. Exit temperatures at one of the fields reach up to 407°C, at conditions of the critical point of seawater, the highest temperatures ever recorded from the seafloor. Fluid and vent field characteristics show a large variability between the vent fields, a variation that is not expected within such a limited area. We conclude from mineralogical investigations of hydrothermal precipitates that vent‐fluid compositions have evolved recently from relatively oxidizing to more reducing conditions, a shift that could also be related to renewed magmatic activity in the area. Current high exit temperatures, reducing conditions, low silica contents, and high hydrogen contents in the fluids of two vent sites are consistent with a shallow magmatic source, probably related to a young volcanic eruption event nearby, in which basaltic magma is actively crystallizing. This is the first reported evidence for direct magmatic‐hydrothermal interaction on a slow‐spreading mid‐ocean ridge.

Effect of Volcanic Activity on the Temperature in the Tropical Upper Atmosphere

AbstractThis article analyzes the volcanic activity influences on temperature change in the tropical upper atmosphere (TUA) using sequential regression, case study and comparison. It is shown that the most volcano‐influenced area in air temperature is in the 70hPa layer of stratosphere at an altitude of about 22km; and the effect gradually decreases beyond or below the height, while the temperature increases in stratosphere but decreases in troposphere at 300hPa near the tropopause. Volcanic activity contributes 45.7% of total variance to the tropical temperature anomaly at 70hPa altitude. Case study on several volcanoes (i.e. Agung, Pinatubo, and El Chichon) of different intensities was conducted. As much as 80% of the temperature anomaly in the TUA would linger for 20 months. Therefore, volcanism is a strong factor causing temperature change in a long period after the explosion.

Chemical evolution of thermal springs at Arenal Volcano, Costa Rica: Effect of volcanic activity, precipitation, seismic activity, and Earth tides

Arenal Volcano in NW Costa Rica, Central America has been active during the last 37 years. However, only relatively low temperature springs have been identified on its slopes with temperatures less than around 60 °C. The springs are clustered on the NE and NW slopes of the volcano, close to contacts between the recent and older volcanic products or at faults that intercept the volcano. This volcano is located in a rain forest region with annual rainfall averaging around 5 m. During the last 15 years, the temperature and chemical composition of 4 hot springs and 2 cold springs have been monitored approximately every 3 months. In addition, two more thermal sites were identified recently and sampled, as well as two boreholes located on a fault NE of the volcano. Scatter plots of chemical species such as Cl and B suggest that the waters in these discharges belong to the same aquifer with a saline end member similar to Río Tabacón at the beginning of the study period (1990) and the deeper borehole (B-2) in 2004. The waters of Quebrada Bambú and Quebrada Fría represent a more dilute end member. Both long-term (over the 15 years) and short-term or seasonal decreases in concentration and steady or decreasing temperature are noted in NW springs. Springs located at the NE show increasing temperatures and ion concentrations, except for bicarbonate that has decreased in concentration for all the springs. This behavior is likely associated with a shallow source for the solutes and heat for this aquifer. To the NW the early lavas and pyroclastic flows have been cooling down, decreasing the contribution of leaching products to the infiltrating waters. To the NE, pyroclastic flows to the N during the last decade are contributing increasing concentrations of solutes and heat throughout water infiltration and circulation within the faults and the surficial drainage that has a NE regional trend. For the short-term or seasonal variations, concentrations of chemical constituents decrease when precipitation increases. However, correlations between concentrations and the number of seismic events per month and the modeled vertical tidal acceleration are also observed. The intrinsic periodic behavior of all these variables influenced by the Earth's rotation can complicate the interpretation of the chemical changes at hot springs. For example, variations in atmospheric pressure can affect the degassing and seismic tremor of a volcano as well as the rate of precipitation. Frequent monitoring and understanding of these variations is essential at every volcano if we want to use the variations in chemical composition of hot springs in volcanic monitoring.

Effects of volcanic activity on mire development: case studies from Hokkaido, northern Japan

Field stratigraphy and macrofossil composition of four mires in Hokkaido, northern Japan, were investigated to test whether tephra deposition induces long-term vegetation shifts. Macroscopic tephras of known origin ranging from 0.5 to > 25 cm in thickness were found in two or more of the study sites, allowing correlation of the stratigraphic development of the mires. Major peat types and position of macroscopic mineral layers were determined in the field, and selected cores were analysed by quantitative macrofossil analysis. Some macrofossil groups and the content of unidentifiable organic matter showed changes in the vicinity of tephra layers, but they did not indicate a clear response pattern of the vegetation or the decomposition dynamics of plant material. Mosses were expected to be most strongly affected by tephra deposition, but even in cases where tephra fell on Sphagnum-dominated vegetation, no fundamental shifts to new plant communities were found. This suggests that disturbance by widespread tephras less than 10 cm thick did not alter site conditions sufficiently to induce shifts in the peat-forming plant communities, or short-term changes did not become manifest in the macrofossil record. A correlation between tephra deposition and vegetation change from nutrient-and mineral-poor bog communities to richer fen communities that had been postulated by some authors was not found at our study sites.

Groundwater in the Lake Myvatn area, northern Iceland: Chemistry, origin and interaction

Lake Myvatn, northern Iceland is unique in that almost all the inflow is supplied through the groundwater by artesian springs. Hardly any surface water is encountered in the area which is covered by young and porous lava fields and transected by faults. The inflow of water and its chemical composition is, therefore, very stable. Geothermal and volcanic activities affect the groundwater system in the Lake Myvatn area and greatly influence the lake's chemistry and thus the biological conditions especially by providing continuous and ample sources of silica and sulphate. Groundwater studies have been intensified in the area during the last years for further developing the Namafjall geothermal field in the area and the Krafla geothermal field about 10 km from Namafjall. Groundwater chemistry was monitored regularly for 2 years at 22 sampling sites and for determining selected indicator constituents in the samples. Concurrently, several tracer tests were performed in the area, the rate of groundwater flow measured, a reservoir model of the groundwater system established. These studies enabled us to divide cold groundwater and geothermal effluent in the Lake Myvatn area into six distinct groups, based on stable isotope ratios, chemical composition and geographical position. The groundwater has separate origins in the local high ground north of Lake Myvatn and the highlands far to the south, possibly as far south as the glacier Vatnajokull. The waters are to a different extent affected by geothermal activity, and effects of volcanic activity were noted during the Krafla fires in 1975–1984. Although these have diminished, they have not completely disappeared. The effluent from Krafla seems to travel to the east of Lake Myvatn and traces of it have not been found to enter the lake. The Namafjall effluent on the other hand travels along fissures to the lake. Attempts made to simulate the evolution of the geothermal water of Krafla and by theoretically titrating local groundwater with rock at elevated temperatures and adding volcanic gas seem promising and result in a composition close to the natural one.

Observations on the effects of volcanic activity on insects and their habitat on White Island

Observations are made on the effect of volcanic activity on pohutukawa forest and its associated insect community on White Island (Whakaari), Bay of Plenty, N.Z.

Effects of Volcanic Activity on Occurrence and Runoff of Debris Flow in Sakurajima Volcano

Effects of Volcanic Activity on Occurrence and Runoff of Debris Flow in Sakurajima Volcano