英文篇名
Investigating Surface Ruptures and Co-Seismic Deformation of 0206 Hualien Earthquake Using Field Survey and Remote Sensing
作者
徐乙君、張中白、郭陳澔、顏君毅、王淳璟、吳柏霖、張有和、張文彥
關鍵字
0206花蓮地震、米崙斷層、地表破裂、遙測技術、同震地表變形
摘要
2018年2月6日23:50在花蓮近海地區發生規模6.4(Mw)的淺層地震,造成花蓮縣北部地區房子倒塌,及多處地表破裂,災害發生位置主要集中於米崙斷層沿線,最南分布至嶺頂斷層的北端。本篇文章針對因0206地震造成之地表變形的地區進行地表地質調查、雷達遙測與大地測量觀察。透過同震地表破裂調查分析,顯示在米崙斷層北段的破裂較集中且規模較大,檢視造成地表破裂的應力方向,可發現除了七星潭區域為北北東-南南西以外,主要應力來源主要都是北北西-南南東方向。雷達遙測與GPS同震變形測量顯示,米崙斷層以及嶺頂斷層以東區域都是向北、北北東的位移,在美崙台地上並有數公分至數十公分的抬升量。而兩條斷層西側都是向南、南南西方向移動,大部分區域也都呈現抬升。經由利用多種資料整合對這次花蓮地震產生之同震地表變形可以得知這次的變形主要受控於近地表的斷層系統,包含米崙斷層及嶺頂斷層。
英文摘要
A deadly earthquake of Magnitude 6.4 (Mw) shook Hualien area in the eve of February 6th, 2018. The earthquake caused damages to infrastructures, toppling of several tall buildings, and ruptures of surfaces. While most of these were proximal to the Milun fault in Hualien city, the damages extended southward to the northern part of the Lingding fault. Field investigation, radar interferometry, and GPS were used to understand the surface ruptures and co-seismic deformations during the earthquake. Based on the results, the northern segment of the Milun fault indicated larger displacements and deformations concentrated more immediately near the fault trace. The principal stress trended NNW-SSE except in the ChiHsinTan area which trended NNE-SSW.
Both radar interferometry and GPS showed that the east of the Milun and Lingding faults were moving north to NNE, and in Meilun tableland, tens of centimeter of co-seismic uplifts were observed. Areas west of these two faults were moving southward and mostly experienced slight uplift.
Our results found that the damages were closely correlated to the near surface faults and fault system.