格陵蘭及其周邊地區的環境噪訊特徵

• Main Authors: 關安達, Guntoro, Andaru Cahyo
• Other Authors: 地球科學系, 饒瑞鈞, Rau, Ruey-Juin
• Format: Thesis
• Language: English
• Published: 2018
• Subjects: 微震; 雙頻; 季節性變化; 海冰; 北大西洋; Microseism; Double Frequency; Seasonal Variation; Sea Ice; North Atlantic Ocean; Arctic; Greenland; Antarc*; Antarctica; Global warming; North Atlantic; Sea ice
• Online Access: http://ir.lib.ncku.edu.tw/handle/987654321/180481; http://ir.lib.ncku.edu.tw/bitstream/987654321/180481/1/index.html

格陵蘭島是世界上最大的島嶼，它對全球變暖研究具有重要的作用。冰覆蓋了格陵蘭島幾乎80％的表面，是南極洲之後第二大冰。如果格陵蘭島上所有的冰都融化了，它將導致全球海平面上升7米。我們使用概率密度函數 - 功率譜密度（PDF-PSD）方法研究格陵蘭島及周邊地區的環境地震噪聲。我們將2016 - 2017年的29個地震台站數據處理成PSD和譜圖。從這個PSD和譜圖中，我們可以分為短週期帶（0.1 - 1 s），次級微震帶（3 - 10 s）和初級微震帶（10 - 20 s）。次級微震頻段顯示出每個台站的季節變化，我們可以發現，冬季最高的功率在2月份達到峰值，但是我們可以在夏季7月或8月的高峰期看到最低的功率。我們將每個台站的psd水平分為四類，第二類微積分帶的峰值為5秒，其他類群在4-5秒處具有最大值。所有簇的主要微觀層次都具有相似的模式，在15秒時具有最高值。每個群的短週期帶在0.3-0.4秒期間具有不同的電平，其中群1具有-152dB，群2具有-138dB，群3具有-145dB，並且群4具有-123dB。正如我們所看到的，格陵蘭的氣候系統與氣候系統有關，3號氣象站幾乎全部位於北極氣候，其他氣候群位於亞北極氣候。我們發現，位於格陵蘭中部的所有地震台站，幾乎在全年都出現了二次微積分高峰。然而，幾乎對於位於東部和西部的地震台，它顯示出二至四個月的二次微震的高峰。這意味著位於中部的台站全年的次微秒震源位置不同。因此，我們要調查格陵蘭地區二次微震的工作因素，並了解二次微震震源的位置。我們也想研究格陵蘭島微震帶與氣候系統之間的關係。 Greenland as the biggest island in the world has an essential role in the global warming research The ice covers almost 80 % of Greenland’s surface and it is the second biggest ice on earth after Antarctica If all the ice on Greenland melted it will cause the rising of sea level in the world by 7 meters We study the ambient seismic noise in Greenland and the surrounding area by using the probability density function – power spectral density (PDF-PSD) method We have processed 34 seismic recording data during 2016 to 2017 for the Z component into PSD and spectrogram From this PSD and spectrogram we can divide the result into the short period band (0 1 – 1 s) secondary microseism band (3 – 10 s) and primary microseism band (10 – 20 s) The secondary microseism band shows a seasonal variation for each station with the highest power level we can find on the winter season with a peak in February however the lowest power we could see on summer with a peak in July or August We classify the PSD level for each station into four clusters one cluster for the secondary microseism band has a peak at 5 second and the other clusters have a maximum value of 4 -5 second The primary microseism level for all the clusters have a similar pattern with the highest value at 15 seconds The short period band for every cluster has a different level with the period at 0 3 – 0 4 second where cluster 1 has -152 dB cluster 2 has – 138 dB cluster 3 has -145 dB and cluster 4 has -123 dB respectively As we can see the period (3 – 10 s) band is related to the climate system in Greenland almost all the stations at cluster 1 located in arctic climate zone and the other clusters located in sub-arctic climate zone We found that all seismic stations which are located in the central part of Greenland it showed two peaks of secondary microseism almost the whole year On the other hand most seismic stations located on the east and west part showed the two peaks of secondary microseism only for two until four months This means the stations located in central part of Greenland has a different source of secondary microseism for a whole year Due to this problem the investigation was conducted to study the factors which work on secondary microseism in Greenland including the location of the source of secondary microseism band This study will also learn the connection between microseism band and climate systems in Greenland 理學院 地球科學系 博碩士論文