Geophysics eJournal最新文献

{"title":"The Deformation Dynamics of the Experimental Adit's Material During a Coal Dust Explosion","authors":"V. Kostenko, Yaroslav Liashok, O. Zavialova, S. Pozdieiev, T. Kostenko","doi":"10.15587/1729-4061.2020.209409","DOIUrl":"https://doi.org/10.15587/1729-4061.2020.209409","url":null,"abstract":"The purpose of this paper is to improve the mechanism that forms an explosive environment within the workings' space from the accumulated coal dust, based on determining the dynamic deformations under the influence of an explosion in the material that contains the examined working. To simulate the dynamic changes in the stressed-deformed state of the rock mass with an experimental adit inside when under the impact of explosive loads, a modern method of finite differences of mathematical-computer modeling has been used. During the research, the mathematical model has been adapted for studying the stressed-strained state of the rock mass that hosts the created experimental adit at the imitation of a dust blast. Additionally, the model takes into consideration the peculiarities of the direct impact of explosion products on the working's wall, as well as their indirect action. The data were acquired on the propagation of the progressive front of seismic waves inside mining rocks that host the experimental working. The parameters of speed and acceleration of the seismic wave components have been established that occur ahead of the shock front, which moves in the gas environment of a mining working during the explosion of a dust-air mixture. This paper reports data on the dynamic processes occurring in a mining massif and on the surface of the experimental working at the chain explosion of a dust-air mixture. The simulation results have made it possible to confirm the hypothesis about the loosening of dust accumulations under the influence of seismic waves, which emerge significantly ahead of the explosion front moving along the working. The modeling results provide an opportunity to improve the systems of protection or localization of the dust-air or dust-gas-air explosions. The existence of seismic waves ahead of the shock front makes it possible to prepare in advance the means for localizing dust explosions","PeriodicalId":210282,"journal":{"name":"Geophysics eJournal","volume":"21 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2020-08-31","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"130091629","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Is a Shock Wave a Source of Seismic Events? Physics, Mechanics, and Kinematics of Mega-Earthquakes","authors":"S. Bychkov","doi":"10.2139/ssrn.3481456","DOIUrl":"https://doi.org/10.2139/ssrn.3481456","url":null,"abstract":"The theory of Mr. Reid’s Elastic recoil, which interprets the origin of earthquakes as the emission of elastic deformation of rocks of the earth's crust, is a sketchy description and is not able to explain in detail the mechanism of earthquakes. This applies not only to the description of exotic types of tremors, such as frost quakes, but also to the classics of Elastic recoil associated with the movement of tectonic plates: seismic events at great depths, an earthquake swarm of a tectonic and volcanic nature. The most important part of seismological research, mega earthquakes with their colossal energy release, does not fit into the framework of the theory of Elastic recoil. For example, the power of the Great Chilean earthquake of 1960 was equivalent to an explosion of 32 billion tons of TNT or 1.33 × 1020 J, which is comparable to the world electricity consumption in 2005 (5⋅1020 J). The energy of a nuclear bomb explosion over Hiroshima was ≈ 15 Kt TNT, which corresponds to the complete conversion into energy less than 1 gram of matter: {15 Kt TNT = 63⋅1012 J, E = mc2, m = E / c2 = 63⋅1012 J. / (3⋅108 m / s) 2 = 0.7 g.} Accordingly, during the Great Chilean earthquake, 1477770 grams of the matter was converted into energy! The calculated figures clearly demonstrate the incomparability of the mechanical strength of terrestrial rocks with such an energy level. Therefore, the question arises: if the source of the earthquake does not have the physical ability to achieve such an energy level, then what is the source of gig earthquakes? We propose to go beyond the theory of Elastic recoil and imagine that an earthquake is generated by a force that suddenly appears in the bowels of the earth and is not related to the forces of elasticity. In this case, the physics and mechanism of earthquakes become easily explainable and simulated. This paper discusses the hypothesis where a shock wave acts as the source of earthquakes and in some case can generate plasma and a thermonuclear reaction. As an example, the physics and mechanics of the occurrence of the mega earthquakes, swarm earthquakes of tectonic, volcanic and deep-focus earthquakes are shown.","PeriodicalId":210282,"journal":{"name":"Geophysics eJournal","volume":"247 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2019-11-05","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"116159063","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Effect of Convolutional Based Local Information with Different Distance Measures in FCM Classification","authors":"Shilpa Suman, Adarsh Kumar, Dheeraj Kumar","doi":"10.2139/ssrn.3356205","DOIUrl":"https://doi.org/10.2139/ssrn.3356205","url":null,"abstract":"Conventional classification procedure assumes that, every pixel consist a single identical class in an image, Fuzzy c-Means (FCM) generally defines membership values for a pixel i.e. any real value between 0 and 1 for each class, in place of enforcing a hard label from among any presumed pure class label set. Fuzzy based FCM classification does not incorporate local spatial information to handle noisy pixels. In this work, Fuzzy local information c-mean (FLICM) and Adaptive Fuzzy local information c-means (ADFLICM) method have been tested to handle noise for remote sensing data classification. These classifiers have been tested with various distance measures. From this work it has been found that all classifiers studied with Canberra distance norm and Fuzziness Factor m=1.1 have given overall best classification accuracy.","PeriodicalId":210282,"journal":{"name":"Geophysics eJournal","volume":"3 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2019-03-20","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"128836965","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Overview of Investigation of Potential CO2 Storage Sites Offshore Japan","authors":"C. Hiramatsu, Kaoru Nagahara, Takuya Miura, Yuji Ichimaru","doi":"10.2139/ssrn.3366423","DOIUrl":"https://doi.org/10.2139/ssrn.3366423","url":null,"abstract":"Japan CCS Co., Ltd. (hereinafter “JCCS”) has been conducting the investigation of potential CO2 storage sites in Japan undercontract to the Ministry of the Environment (hereinafter “MOE”) and Ministry of Economy, Trade and Industry (hereinafter“METI”) of Japan since 2014.<br><br>We have been conducting a number of 2D/3D seismic surveys and geological interpretation at pre-selected areas in offshore Japan, in order to identify prospective sites from among these areas. Several candidate sites will be selected from these prospective sites, and exploratory wells will be drilled to confirm the presence of geological conditions necessary for storage.<br>The drilling will be followed by the construction of a geological model and flow simulation. The final goal of the current scope of work is to recommend three potential sites for CO2 geological storage to MOE and METI by around 2021.<br><br>The main selection criteria of a potential storage site are as follows:<br> &gt; The potential sites should be located in offshore areas<br> &gt; Capacity of each site is to store over 100 million tonnes of CO2<br> &gt; There are no active faults close to the site<br> &gt; The existence of a CO2 emission source near the site is not taken into consideration<br> &gt; The method of CO2 transportation to the site is not taken into consideration<br> &gt; Producing oil and gas fields are excluded (site is not for EOR purpose)<br> &gt; There is no environmental protected area around the site<br><br>In addition, a preferable condition is whether the site can be reached by directional drilling from onshore, as is the case for the Tomakomai CCS Demonstration Project. In this project, two directional CO2 injection wells were drilled with horizontal reach of over 3,000 meters, saving considerable construction cost as it was not necessary to bring in an offshore drilling rig, or to lay<br>expensive subsea pipelines and related offshore facilities.<br><br>The 2D/3D seismic survey conducted in the investigation of potential sites is the most effective method to delineate the geological features of the subsurface. 2D seismic surveys are conducted to grasp the regional geological features over a wide range such as 50 x 100 km, and if prospective structures for CO2 geological storage are identified, 3D seismic surveys over a smaller range (e.g., 10 x 10 km) will be executed to delineate the geological features more precisely.<br><br>When necessary, we employ state-of-art seismic acquisition and processing technology utilized in the oil and gas industry to accomplish our objectives.<br><br>In one of the 3D seismic surveys, we have conducted a seamless 3D seismic survey across the transition zone between shallow marine and onshore. As the possible presence of active faults was suspected in the transition zone, there was a need to collect data from the shallow marine continuously to the onshore area. Although the survey has taken time and effort, we were able to fill the gap in the exist","PeriodicalId":210282,"journal":{"name":"Geophysics eJournal","volume":"434 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"1900-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"133238894","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}