Periodicity in the BrO/SO2 molar ratios in the volcanic gas plume of Cotopaxi and its correlation with the earth tides during the eruption in 2015

• Verfasst von: Dinger, Florian [VerfasserIn]
• Verfasst von: Bobrowski, Nicole [VerfasserIn]
• Verfasst von: Warnach, Simon [VerfasserIn]
• Verfasst von: Platt, Ulrich [VerfasserIn]
• Verfasst von: Wagner, Thomas [VerfasserIn]
• Titel: Periodicity in the BrO/SO2 molar ratios in the volcanic gas plume of Cotopaxi and its correlation with the earth tides during the eruption in 2015
• Verf.angabe: Florian Dinger, Nicole Bobrowski, Simon Warnach, Stefan Bredemeyer, Silvana Hidalgo, Santiago Arellano, Bo Galle, Ulrich Platt, and Thomas Wagner
• Jahr: 2017
• Umfang: 28 S.
• Fussnoten: Die Zahl 2 ist im Titel tiefgestellt ; Gesehen am 21.02.2020
• Titel Quelle: Enthalten in: Solid earth
• Ort Quelle: Göttingen : Copernicus Publ., 2010
• Jahr Quelle: 2017
• Band/Heft Quelle: (2017), Seite 1-28
• ISSN Quelle: 1869-9529
• DOI: doi:10.5194/se-2017-89
• Datenträger: Online-Ressource
• Sprache: eng
• K10plus-PPN: 1569815496

Abstract

We evaluated NOVAC (Network for Observation of Volcanic and Atmospheric Change) gas emission data from the 2015 eruption of Cotopaxi volcano (Ecuador) for BrO/SO₂ molar ratios. Statistical analysis of the data revealed a conspicuous periodic pattern with a periodicity of about two weeks in a three month time series. While the time series is too short to rule out a chance recurrence of transient geological or meteorological events as a possible origin for the periodic signal, we nevertheless took this observation as a motivation to examine the influence of natural forcings with periodicities of around two weeks on volcanic gas emissions. One strong aspirant with such a periodicity are the Earth tides, which are thus central in this study. We present the BrO/SO₂ data, analyse the reliability of the periodic signal, discuss a possible meteorological or eruption-induced origin of this signal, and compare the signal with the theoretical ground surface displacement pattern caused by the Earth tides. Central result is the observation of a significant correlation between the BrO/SO₂ molar ratios with the North-South and vertical components of the calculated tide-induced surface displacement with correlation coefficients of 47 % and 36 %, respectively. From all other investigated parameters, only the correlation between the BrO/SO₂ molar ratios and the relative humidity in the local atmosphere resulted in a comparable correlation coefficient of about 33 %.