Relative Sea Level Trends for the Coastal Areas of Peninsular and East Malaysia Based on Remote and In Situ Observations

Abstract

Absolute sea-level rise has become an important topic globally due to climate change. In addition, relative sea-level rise due to the vertical land motion in coastal areas can have a big societal impact. Vertical land motion (VLM) in Southeast Asia includes a tectonically induced component: uplift and subsidence in plate boundary zones where both Peninsular and East Malaysia are located. In this paper, the relative sea-level trends and (seismic cycle-induced) temporal changes across Malaysia were investigated. To do so, the data (1984–2019) from 21 tide gauges were analyzed, along with a subset (1994–2021) of nearby Malaysian GNSS stations. Changes in absolute sea level (ASL) at these locations (1992–2021) were also estimated from satellite altimetry data. As a first for Peninsular and East Malaysia, the combination ASL minus VLM was robustly used to validate relative sea-level rise from tide-gauge data and provide relative sea-level trend estimates based on a common data period of 25+ years. A good match between both the remote and in situ sea-level rise estimations was observed, especially for Peninsular Malaysia (differences < 1 mm/year), when split trends were estimated from the tide gauges and GNSS time series to distinguish between the different VLM regimes that exist due to the 2004 Sumatra–Andaman megathrust earthquake. As in the south of Thailand, post-seismic-induced negative VLM has increased relative sea-level rise by 2–3 mm/year along the Andaman Sea and Malacca Strait coastlines since 2005. For East Malaysia, the validation shows higher differences (bias of 2–3 mm/year), but this poorer match is significantly improved by either not including data after 1 January 2014 or applying a generic jump to all East Malay tide gauges from that date onwards. Overall, the present relative sea-level trends range from 4 to 6 mm/year for Malaysia with a few regions showing up to 9 mm/year due to human-induced land subsidence.

Coastal Evolution of Satingpra Peninsula, Songkhla Province: Implications for Understanding Songkla Lagoon Formation

“…In contrast, subsequent vertical land subsidence was seen to be within the range of 0.5 ± 0.12 m/ka. In addition, the data obtained from the GET1 and GET2 stations indicates the need to take into account human subsidence factors, such as sediment compaction and groundwater extraction [44]. This available evidence indicates that both tectonic and human-driven processes have exerted influence on Peninsula Malaysia.…”

Accuracy assessment of quasi-seamless hydrographic separation models in Malaysian waters

“…The available evidence suggests that subsidence in Peninsular Malaysia was triggered by the 2004 Mw 9.2 Sumatra-Andaman earthquake. According to Simons et al (2023), this seismic event initiated a process that resulted in gradual sinking of the land, with a recorded decrease of 3-5 cm over the past 17 years. In East Malaysia, the rates of subsidence are comparatively lower, ranging from −0.5 to −1.0 mm per year, leading to a total landfall of 2-3 cm during the same period.…”

Influence of Behavioural Factors on Mobile Phone Usage among Fishermen to Seek Climate Change Related Information

“…Climate change in Malaysia is not a new phenomenon. Some signs of climate change such as increasing temperatures How et al (2023), instability of rainfall patterns Wan Azli (2010), rising sea levels Simons et al (2023), the frequency of strong winds and big waves Razali et al (2010), the instability of the east coast monsoon season Suhaila et al (2010) has already been detected in this region.…”