Study on the determination of ancient shoreline altitude based on seismic crustal deformation deduced emergent shoreline topography

2023 Fiscal Year Final Research Report

• Project/Area Number: 18K01120
• Research Category: Grant-in-Aid for Scientific Research (C)
• Allocation Type: Multi-year Fund
• Section: 一般
• Review Section: Basic Section 04010:Geography-related
• Research Institution: Ehime University
• Principal Investigator: ISHIGURO Satoshi 愛媛大学, 法文学部, 准教授 (90547499)
• Project Period (FY): 2018-04-01 – 2024-03-31
• Keywords: 離水海岸地形 / 地震生地殻変動 / LiDAR / SfM-MVS

Outline of Final Research Achievements

The purpose of this study is to establish a topographic measurement method to determine with high accuracy the former shoreline elevation corresponding to the detached coastal topography associated with seismic crustal deformation. For this purpose, we have attempted to measure the detailed topography of the upper surface of the reef crest in the coral reef topography developed in the northern part of Yoron Island, but it was found to be difficult to create a detailed topographic model. Therefore, we selected the target area as the remote coastal topography in Murakami City, Niigata Prefecture, and demonstrated the possibility of measuring detailed remote coastal topography by using portable LiDAR. However, it was also found that the portable LiDAR has some difficulties in handling in the field, so it is necessary to establish an appropriate data acquisition method in the future.

Free Research Field

変動地形学

Academic Significance and Societal Importance of the Research Achievements

地震性地殻変動にともなう離水海岸地形に対応する旧汀線高度を、高精度に決定することは、過去に生じた地震生地殻変動量を正確に計測することができることから、地震の規模及び発生間隔を高精度に推定するために役立つ。このことは、将来発生が予測される、海岸隆起を伴う地震について、その規模等を推定することに繋がり、ひいては災害の誘因たる地震の基礎資料となる。また、地形を正確かつ細密に計測する手法を確立することは、海岸隆起を伴う地殻変動のみならず、地変を伴う現象全般への展開が可能である点で、波及効果は大きい。