從InSAR與GNSS觀測探討2016至2021年間黃石陷落火山口的地表變形;Deformation of Yellowstone Caldera from InSAR and GNSS Observations, 2016-2021

NCU Institutional Repository > 地球科學學院 > 地球物理研究所 > 博碩士論文 > Item 987654321/99271

jsp.display-item.identifier=請使用永久網址來引用或連結此文件: https://ir.lib.ncu.edu.tw/handle/987654321/99271

题名:	從InSAR與GNSS觀測探討2016至2021年間黃石陷落火山口的地表變形;Deformation of Yellowstone Caldera from InSAR and GNSS Observations, 2016-2021
作者:	陳虹瑄;Chen, Hong-Xuan
贡献者:	地球科學學系碩士班
关键词:	黃石陷落火山口;InSAR;GNSS;地表變形;模型反演;Yellowstone Caldera;InSAR;GNSS;surface deformation;source modeling
日期:	2026-01-27
上传时间:	2026-03-06 18:29:17 (UTC+8)
出版者:	國立中央大學
摘要:	本研究利用2016-2021年Sentinel-1衛星資料與GNSS三分量，建立黃石地區地表變形，並探討其控制變形的機制。研究首先以DInSAR觀察空間地表變化，並進一步透過MintPy建立SBAS-InSAR時間序列，搭配大氣校正、相位坡度校正及地形殘差校正，以獲得兩時段（2016-2018、2019-2021）的可靠地表位移場。GNSS與InSAR比對結果顯示，兩時段平均誤差約5-12 mm，證實InSAR時序結果具一致性。結果顯示，2016-2021年間黃石陷落火山口整體呈現緩慢下沉，而西北邊界變形呈區域性差異：2016-2018年Norris Geyser Basin（NGB）與Terrace Spring（TS）皆抬升，抬升中心位於NGB；2019-2021年NGB轉為下沉，而TS持續抬升且幅度略增，並證實TS屬於獨立變形系統。為探討變形來源，本研究採用VMOD進行非線性反演與貝葉斯取樣，結果顯示NGB可由深度約5-6 km的Mogi收縮源解釋；TS則對應深度約2-3km、半徑約10 km的Penny-shaped crack壓力源。兩者在深度與位置上皆相互獨立。綜合地震活動、地震層析成像結果的低VP/VS結構、二氧化碳通量以及地質構造背景，本研究提出黃石西北邊界的雙系統熱液模式：NGB為裂隙通暢、易釋放流體的開放系統，而TS為低滲透性區域、易封存流體的封閉系統，導致兩區呈現反向變形。不同的構造與岩性決定了兩區域的滲透性差異，是驅動近年地表變形在空間上差異的主因。本研究不僅為黃石流體與變形關聯性提供新約制，亦進一步以地表變形證據支持TS地表淺處存在二氧化碳聚集，並凸顯TS區域持續監測的必要性。 ;This study investigates surface deformation in Yellowstone between 2016 and 2021 using Sentinel-1 synthetic aperture radar (SAR) observations and three-component GNSS measurements, with the aim of characterizing surface deformation patterns and identifying the mechanisms controlling deformation. We first applied differential InSAR (DInSAR) to examine spatial deformation signals and then generated small-baseline subset (SBAS) InSAR time series using MintPy. To improve the reliability of the time series results, corrections for atmospheric delays, phase ramps, and residual topographic errors were implemented. Deformation fields were analyzed for two time intervals (2016-2018 and 2019-2021) to capture potential temporal changes. Comparison between InSAR-derived displacement and GNSS displacement projected onto the LOS direction indicates mean discrepancies of approximately 5-12 mm for both periods, suggesting that the InSAR time series results are internally consistent and robust. The results reveal that the Yellowstone caldera experienced overall gradual subsidence during 2016-2021, while deformation along the northwest caldera boundary shows strong spatial heterogeneity. During 2016-2018, both Norris Geyser Basin (NGB) and Terrace Spring (TS) exhibited uplift, with the main uplift center located near NGB. In contrast, during 2019-2021, NGB transitioned to subsidence, whereas TS continued uplifting with a slightly increased magnitude. This temporal divergence indicates that TS represents an independent deformation system rather than a peripheral response to deformation centered at NGB. To constrain the deformation sources, we performed nonlinear inversion and Bayesian sampling using the VMOD (Versatile Modeling of Deformation) framework. The results suggest that deformation at NGB can be explained by a contracting Mogi source at ~5-6 km depth. In comparison, deformation at TS is best represented by a pressurized penny-shaped crack at ~2-3 km depth with an estimated radius of ~10 km. These two sources are distinct in both depth and location, supporting the interpretation that NGB and TS are governed by mechanically independent subsurface systems. To interpret the physical origin of the modeled sources, we integrated independent constraints from seismicity patterns, low VP/VS anomalies from seismic tomography, surface CO₂ flux measurements, and geological-structural context. Together, these observations support a dual hydrothermal system model for the northwest boundary of the Yellowstone caldera. NGB is characterized as an open hydrothermal system, where well-developed fractures and high permeability facilitate fluid circulation and efficient pressure release, consistent with the observed subsidence/deflation during 2019-2021. In contrast, TS is interpreted as a closed, low-permeability system, where fluids and volatiles are more readily trapped and accumulate pressure, producing persistent uplift. The contrast in permeability controlled by lithology and structural architecture is inferred to be the primary factor driving the spatially variable deformation observed in recent years. Overall, this study provides new constraints on the coupling between subsurface fluids and surface deformation in Yellowstone, supports shallow CO₂ accumulation beneath TS inferred from deformation evidence, and highlights the importance of continued geodetic monitoring of the TS region.
显示于类别:	[地球物理研究所] 博碩士論文

文件中的档案:

档案	描述	大小	格式	浏览次数
index.html		0Kb	HTML	5	检视/开启

在NCUIR中所有的数据项都受到原著作权保护.

社群 sharing

数据加载中.....