IOSR Journal of Applied Geology and Geophysics (IOSR-JAGG) e-ISSN: 2321–0990, p-ISSN: 2321–0982.Volume 9, Issue 1 Ser. I (Jan. – Feb. 2021), PP 01-11 www.iosrjournals.org DOI: 10.9790/0990-0901010111 www.iosrjournals.org 1 | Page Seismic noise characteristics of Maitri broadband seismic station in Antarctica: using power spectral density estimation Satish Saha and D. Srinagesh CSIR-National Geophysical Research Institute(NGRI), Uppal Road, Hyderabad-500007, India __________________________________________________________________________________________ Abstract: The seismic noise analysis is very useful tool for characterizing the performance of the existing seismic stations and it should be used as a first step in reducing the noise level in seismic signals. The main indicator of the quality of a seismic station is the level of the noise recorded in the absence of seismic signal. The level of noise recorded on seismometer can be reduced by locating the station away from human activity, selecting good geology and ensuring good seismic vault design and constructed at site, including thermal insulation and excellent ground coupling of broadband seismometer. In the year 1998 an ice free, rocky area on Schimacher Oasis was selected to build the Indian second research station “Maitri” (70°45’52” S and 11°44’03” E) in East Antarctica. The seismic background noise is studied at Maitri broadband seismic station operated in continuous mode till date. To access the performance of Maitri broadband seismic station and to investigate the characteristics of different types of noises dominated at site. The standard tool to analyse the noise performance is the power spectral density (PSD), where the frequency content of the waveform from a period is evaluated. The power spectral density and probability density function are calculated using seismic data from summer months period recorded at Maitri, Antarctica i.e. from January-February 2018 and compared with the winter month period i.e. September 2018. The data are in miniSEED format. The PSDs of seismic background noise are determine using seismic data free from earthquakes and instrument calibration/mass centring pulses [4]. The individual PSDs can be combined to produce a probability density function (PDF) for the PSDs.These PDF are a very powerful tool that can be used to rapidly evaluate the quality of seismic station. The power spectral density of ambient background noise is calculated and compared with the new global noise model. SQLX is unique seismological data analysis tool useful for both data quality control and research, follows the methodology of McNamara and Buland (2004). SQLX converts time-domain data into Power Spectral Density (PSD) equivalents in the frequency domain. PDF noise plots are useful for characterizing the current and past performance of existing broadband seismometer, for detecting operational problems within the recording system, and for evaluating the overall quality of data for particular station [9]. The background noise at site can also vary over time, as human activity in the vicinity can change and tracking the noise allows understanding the performance of the station through time. The result suggests that the noise levels of Maitri broadband seismic station are within the limit of the new global high and low noise model. Keyword: Seismic Noise Analysis, Maitri, human activity, Antarctica, Power Spectral Density (PSD), Probability Density Function (PDF). --------------------------------------------------------------------------------------------------------------------------------------- Date of Submission: 05-01-2021 Date of Acceptance: 20-01-2021 --------------------------------------------------------------------------------------------------------------------------------------- I. Introduction Antarctica is the world’s greatest natural laboratory and attracts scientists for research. It is a stable platform for caring out scientific investigations. Being far away from all industrial areas remains an unpolluted region. The changes due to pollution all over the Globe can be monitored from here. Antarctica, the world’s windiest, coldest and the stormiest continent has an area of 14 million sq. km. It is also called a pulsating continent as the size keeps on increasing and decreasing during different seasons. The continent starts freezing during winter i.e. for a month’s start from March to October known as winter months i n Antarctica, increasing the size to hundreds of km and the same starts breaking up as the summer approaches i.e. for months from late November to February months. It has one of the most hospitable terrains and harsh climate in the world. The 30 countries currently involved in research in the continent are authorized signatories of the Antarctic treaty, which is mandatory to operate research hubs in the continent. The population of the scientists operating in various research stations varies from 4000 during summer to a 1000 during the winter. CSIR-National Geophysical Research Institute (NGRI) with the support from ESSO-National Centre for Polar and Ocean research established a permanent seismic station was fully commissioned on 26th January, 1998 with analog and short period digital seismograph. This seismological observatory was further up-graded with the installation of broadband seismic station in January 2001 at the Indian base station Maitri, East Antarctica. This broadband seismic data was contributed to International Seismological Observatory (ISC), U.K for the preparation of