Abstract
The relative sea-level changes from tide gauges in the Korean peninsula provide essential information to understand the regional and global mean sea-level changes. Several corrections to raw tide gauge records are required to account for coastal vertical land motion (VLM), regional and local coastal variability. However, due to the lack of in-situ measurements such as leveling data and the Global Navigation Satellite System (GNSS), making precise assessments of VLM at the tide gauges is still challenging. This study aims to address the above limitation to assess the VLM in the Korean tide gauges using the time-series Interferometric Synthetic Aperture Radar (InSAR) technique. For 10 tide gauges selected in the Korean peninsula, we applied the Stanford Method for Persistent Scatterers (StaMPS)—Small Baseline Subset (SBAS) method to C-band Sentinel-1 A/B Synthetic Aperture Radar (SAR) data acquired during 2014/10–2020/05, with the novel sequential interferograms pair selection approach to increase the slowly decorrelating filtered phase (SDFP) pixels density near the tide gauges. Our findings show that overall the tide gauges in the Korean peninsula are stable, besides the largest VLM observed at Pohang tide gauge station (East Sea) of about −26.02 mm/year; also, higher rates of uplift (>1 mm/year) were observed along the coast of Yellow Sea (Incheon TG and Boryeong TG) and higher rates of subsidence (<−2 mm/year) were observed at Jeju TG and Seogwipo TG. Our approach estimates the rate of VLM at selected tide gauges with an unprecedented spatial and temporal resolution and is applicable when the in-situ and GNSS observations are not available.
Highlights
The vulnerability of coastal areas due to sea-level rise inundation has received increasing attention in the years since the rise of the global mean sea level of about 11–16 cm in the 20th century [1]
The relative sea changes derived from tide gauges are affected by vertical land motion and Global Navigation Satellite System (GNSS) vertical velocities at collocated tide gauge stations and in-situ leveling provide insight into such ground motions
The highest rate of vertical land motion was estimated at Pohang tide gauge station at −26.02 mm/year and has a good agreement when compared to linear trends of collocated GNSS vertical velocities (−26.35 mm/year) and in-situ leveling measurements (−25.89 mm/year)
Summary
The vulnerability of coastal areas due to sea-level rise inundation has received increasing attention in the years since the rise of the global mean sea level of about 11–16 cm in the 20th century [1]. The sea level is forecasted to rise about 0.5 m to 2 m in the 21st century due to climate change that is driven by carbon emissions and Antarctica’s ice sheet instability [1,2,3]. Since the sea-level rise has direct impacts on small islands and low-lying coastal regions where immense growth of population is taking place, reliable sea-level projections are extremely important for mitigation planning from flooding and coastal erosion [4]. Global monitoring of oceans for sea-level changes is mainly accomplished by tide gauge records [5,6] and satellite altimetry estimates [7,8]. The network of tide gauges distributed on the world coasts and inland played a vital role in understanding sea-level changes [9]
Sign-in/Register to view highlights & summary Sign-in/Register to access full text options 
Free) 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a call
