• Geophysics and Geophysical Exploration
• /
• v.22 no.2
• /
• pp.62-71
• /
• 2019

We conducted DC resistivity and MT survey to obtain the resistivity structure of the central Myanmar basin. We tried to analyze the underground structure through the resistivity variation of Myanmar by performing representative geophysical survey methods because researches on the electrical resistivity structure are insufficient in Myanmar. The electrical resistivity is expected to be low considering the marine sedimentary rocks composed of shale and sandstone in this area. The DC resistivity and MT survey were carried out using SmartRho of Geolux Co., Ltd. and MTU-5A of Phoenix geophysics Ltd., respectively, to visualize the electrical resistivity structure of study area. DC resistivity and MT survey showed an electrical resistivity less than dozens of ohm-m within the depth of 100 m. In particular, MT survey data were almost similar to TM and TE modes in the frequency range above 1 Hz. The two-dimensional inversion of MT data showed a subsurface structure with low resistivity below 150 ohm-m divided into east-west direction. We confirmed that the inversions of DC resisitivity and MT data along an overlapped survey line represented similar results. In the future, considering the high electrical conductivity, it would be effective to perform DC resistivity and MT survey simultaneously to study the electrical resistivity structure of the central Myanmar basin.

• Journal of the Korean earth science society
• /
• v.34 no.6
• /
• pp.575-587
• /
• 2013

DC electrical and electromagnetic survey was applied to evaluate the reserve of an iron mine site. We analyzed the borehole cores and the cores sampled from outcrops in order to decide which geophysical method was efficient for the evaluation of iron mine site and to understand the geological setting around the target area. Based on the core tests for specific weight, density, porosity, resistivity and P-wave velocity, showing that the magnetite could be distinguishable by the electrical property, we decided to conduct the electrical survey to investigate the irone mine site. According to previous studies, the DC electrical survey was known to have various arrays with high resolutions effective to the survey of the iron mine site. However it was also known that the skin depth is too shallow to grasp the deep structure of iron mine. To compensate the weakness of the DC electrical method, we applied the MagnetoTelluric (MT) survey. In addition, a Controlled Source MT (CSMT) method was also applied to make up the shortcoming of MT method which is weak for shallow targets. From the DC electrical and MT survey, we found a new low resistivity zone, which is believed to be a magnetite reserve beneath the old abandoned mine. Therefore, this study was confirmed for additional utility value.

• Journal of environmental and Sanitary engineering
• /
• v.18 no.2
• /
• pp.16-26
• /
• 2003

Analysis of benthic macroinvertebrate community and biological estimation of water quality was conducted at the national park of Mt. Jiri and its nearby area in Gurye, Sancheong and Hadong-gun from June to November, 2002. Total taxa of benthic macroinvertebrates were 124 species, 45 families, 15 orders, 5 classes in 3 phyla. Aquatic insects were 33 species in ephemeroptera, 28 species in Trichoptera, 21 species in plecoptera, 13 species in Diptera, 8 species in odonata, 5 species in hemiptera and 5 species in coleoptera, respectively. Non-insects were 5 species in Mollusca, 2 species in Hirudinea, 1 species in oligochaeta and 1 species in crustacea, respectively. Ephemeroptera, trichoptera and plecoptera as indicators in clean water were very abundant. Occurrence species at each survey area was 68 species at Mt. 1025-goji, 59 species at Mt. Eungseok-bong, 57 species at Mt. Wangdeung-jae, 50 species at Mt. Cheonwang-bong and 39 species at Mt. 645-goji, respectively. Mean species diversity indices at Mt. Cheonwang-bong, Mt. 1025-goji, Mt. Wangdeung-jae, Mt. Eungseok-bong and Mt. 645-goji were 3.33, 3.03, 3.41, 3.02 and 2.91, respectively, According to the saprobic system based on the species diversity indices of benthic macroinvertebrates, most survey areas except some sites are determined as Limnosaprobic area.

• Geophysics and Geophysical Exploration
• /
• v.9 no.4
• /
• pp.261-270
• /
• 2006

Two-dimensional (2-D) inversion of magnetotelluric (MT) data for two survey lines having south-north direction from Jeju Island has been carried out. Broad band MT sounding curves with good quality could be gathered by performing audio-frequency magnetotelluric (AMT) survey during the MT survey and by operating the remote reference in Kyushu Island, Japan. Comparison of the 2-D inversion model using MT band only and that using both AMT and MT bands for the field data as well as for the data from numerical 2-D modeling said that high frequency information from AMT survey can be useful for interpreting not only the shallow part but also the deep structures, especially when the formation is resistive. The 2-D inversion models of field data show a thick layer having around 10 ohm-m in the depth of a few hundred meters throughout the survey area, which can be considered as the unconsolidated sedimentary layer. And they also show a conductive anomaly at the central part of each survey lines. It can be either the effect of the surrounding sea water, or the structures due to ancient volcanic events. But unfortunately by now, we do not have any further information about the anomaly.

• 한국신재생에너지학회:학술대회논문집
• /
• 2006.06a
• /
• pp.434-437
• /
• 2006

Though numerous drilling has been performed in Jeju Island for development of ground water, the wells are mostly located along the coast lines or at low altitude area, and can hardly be found on the mid-mountain area. Two-dimensional magnetotelluric (MT) surveys have been carried out to cover the lack of geological Informal ion on the mid-mountain area and to figure out any possible structures or evidences for deep geothermal energy remained. Two-dimensional (2-D) inversion of MT data for four survey lines surrounding the Halla mountain show a thick layer having around 10 ohm-m in the depth of a few hundred meters throughout the survey area, which can be considered as the unconsol idated sedimentary layer. And they also show a conductive anomaly extending to more than 2km depth at the central part of each survey lines, which can possibly be related with old volcanic activities during the formation of Halla Mt.. Further seological/geophysical investigations should be followed.

• 한국지구물리탐사학회:학술대회논문집
• /
• 2005.05a
• /
• pp.21-26
• /
• 2005

Two-dimensional (2-D) inversion of magnetotelluric (MT) data for two survey lines having south-north direction from Jeiu Island has been carried out. The 2-D models show a thick layer having around 10 ohm-m in the depth of a few hundred meters throughout the survey area, which can be considered as the unconsolidated sedimentary layer. And they also show a conductive anomaly at the central part of each survey lines. But unfortunately by now, we do not have any further information about the anomaly. Comparison of the 2-D inversion model using MT band only and that using both AMT and MT bands said that it is helpful for us to include AMT band as well as MT band in the inversion to interpret not only the shallow part but also the deep structures.

• Journal of Industrial Technology
• /
• v.41 no.1
• /
• pp.21-24
• /
• 2021

In this study, the development and production of electric vehicles and hydrogen vehicles are presented as a method for realizing carbon-neutral. Accordingly, the demand and need for development of underground metal mineral resources such as copper and nickel has increased. The research was carried out using MT survey, which is very useful for deep exploration such as mineral resources and oil exploration because of it's low cost and explorable depth. In Korea, there are very few cases of MT exploration in terms of mineral development, so the study was conducted based on the MT exploration conducted previously in AusLAMP, Australia. Through comparative analysis of the MT exploration data conducted to identify the ore body in the deep area of the Olympic Dam in Australia, with the data directly calculated in 2D inversion, it was confirmed that it can have a positive effect on the possibility of resource development and carbon neutrality using MT exploration in Korea.

• Journal of Practical Agriculture & Fisheries Research
• /
• v.12 no.1
• /
• pp.11-19
• /
• 2010

This study was carried out to investigate the characteristics survey of Clavicorona pyxidata strains. C. pyxidata are selected 3 kinds of strains collected in GWANG DEOCK Mt., DO BONG Mt., and BUK HAN Mt., Mycelial growth of C. pyxidata collected from GWANG DEOCK and BUK HAN Mt. is 64mm, 60mm for 18days respectively. DO BONG Mt strain is 85mm for 9 days. Transparent crystal body of C. pyxidata mycelia were appeared by microscopic examination of 100 magnification. Optimal temperature of mycelial growth in C. pyxidata strains are 25~30℃ respectively.

• Korean Journal of Environment and Ecology
• /
• v.22 no.3
• /
• pp.221-229
• /
• 2008

This study observed and compared phenological changes in the spring for some native woody plants growing at Mt. Jumbong and Mt. Bongeui located at central districts of our country, and also inquired into the phenological difference subsequent to microclimate change by measuring its related environment factors as well. The average air temperature at a survey point of Mt. Jumbong from January to May in 2004 was $4.1^{\circ}C$ lower than that of Mt. Bongeui. As for the soil temperature in April by a survey section within Mt. Jumbong, the soil temperature on the west and northwest slopes was $1.8^{\circ}C$ and $4.4^{\circ}C$ lower than that of the south slope, respectively. It was found that the earliest tree species in a flowering period was Lindera obtusiloba among the sample woody plants and its flowering began in late March at Mt. Bongeui and in early April at Mt. Jumbong. The flowering of the same species began faster on the south slope than the west or north slope; in case of the tree species flowering in early spring, there appeared about two-week interval between the survey sites. Likewise, leafing time of the same species was two weeks earlier at Mt. Bongeui(in mid-April) than at Mt. Jumbong(in early May). Nuttonson's Index and Year Day Index for the flowering and leafing time of the same species showed similar value between the survey sites. It is analyzed that the transition in phenological phases between the sites is mainly caused by temperatures; further, it is implied that the climate changes and rise in temperatures could expedite the changes in phenological phases more than ever.

• Journal of environmental and Sanitary engineering
• /
• v.14 no.4
• /
• pp.50-68
• /
• 1999

The present study was performed to examine on the fauna and standing crops of benthic macroinvertebrates in Pongwha and Youngwol region of upper parts of south han river and Naktons river. The Actual site suvry was caried out on the two times during the April·June to October·November, 1988. Main five areas are Mt. Awrawe(1,067m), Mt. Sontal (1,236m), Mt. Munsu(1,206m), Peak Okyopong(357m) and Mt. Pungnak(760m) area. Total taxa of benthic macroinvertebrates of the study area were 118 species, 45families12 orders, 5 classes in 4 phyla. Occurrence species according to the major taxa of aquatic insects were 35 species (29.66%) in ephemeroptera, 25 species(21.19%) in trichoptera, 25 species(21.19%) hemiptera, 1 species(0.85%) in megaloptera. Non-aqautic insect were 5 species in mollusca, 3 ratio was 8.5 percent. Occurrence species(plecoptera) at clean waters were appeared 12 species at Mt. Awrawe and Sontal area. Occurrence species at each survey area was 67 species at Mt. Awrawe area, 60 species at Mt. Sontal area, 43 species at Mt. Munsu area, 37 species at Mt. P'ungnak area and 34 species at Peak Okyo area, respectively. Species diversity indices were 2.96~3.80 at Mt. Awrawe area, 2.79~3.62 at Mt. sontal area, but 2.64~3.12, 1.59~2.46 and 1.98~2.59 at, Mt. Munsu, P'ungnak and Peak Okyo area, respectively. In this region, occurrence species and individual density were smaller than that of Dong river with good habitat, but those were more abundant than that of Poseong river with similar environment conditions. Therefore, occurrence species and individual density of the present survey region were appeared as somewhat abundant.