72
The history of sea-level change in Malaysia is different from that of the eastern
United States (see the chapter by Kemp and Horton). There are two main reasons for
this that operate over different time scales. As polar continental glaciers melted over
the last 20,000 years, sea level in both areas rose ~120 m, flooding the continental
shelves that were once land. In eastern US, this sea-level rise continues today. In
Malaysia, sea level rose to a maximum of ~3 m above present by 6000 years ago
then fell to the modern level, constructing a regressive coastal plain. Sea level is
now rising again slowly in this region.
Because of its relative tectonic stability, the eastern US has experienced multiple,
alternating periods of high and low sea level for over two million years. These periods of high sea level were global in scale. In the southeastern US, they produced a
broad coastal plain characterized by terraces (see the chapter by Farrell) that step
down in elevation and decrease in age towards the coast. In Peninsular Malaysia,
also considered relatively tectonically stable over the last two million years, the
surficial deposits of the coastal plain consist solely of sediment associated with the
Fig. 5.2 Map of Peninsular Malaysia shows the areas surveyed by the author (outlined in yellow).
(Basemap from https://www.maps.ngdc.noaa.gov; modified and labelled by the author)
P. R. Parham
The history of sea-level change in Malaysia is different from that of the eastern
United States (see the chapter by Kemp and Horton). There are two main reasons for
this that operate over different time scales. As polar continental glaciers melted over
the last 20,000 years, sea level in both areas rose ~120 m, flooding the continental
shelves that were once land. In eastern US, this sea-level rise continues today. In
Malaysia, sea level rose to a maximum of ~3 m above present by 6000 years ago
then fell to the modern level, constructing a regressive coastal plain. Sea level is
now rising again slowly in this region.
Because of its relative tectonic stability, the eastern US has experienced multiple,
alternating periods of high and low sea level for over two million years. These periods of high sea level were global in scale. In the southeastern US, they produced a
broad coastal plain characterized by terraces (see the chapter by Farrell) that step
down in elevation and decrease in age towards the coast. In Peninsular Malaysia,
also considered relatively tectonically stable over the last two million years, the
surficial deposits of the coastal plain consist solely of sediment associated with the
Fig. 5.2 Map of Peninsular Malaysia shows the areas surveyed by the author (outlined in yellow).
(Basemap from https://www.maps.ngdc.noaa.gov; modified and labelled by the author)
P. R. Parham