CHARACTERISTICS OF PALYNOMORPH DUE TO CLIMATE CHANGE IN SUMBA DEEP SEA SEDIMENT SINCE THE LATE PLEISTOCENE, EAST NUSA TENGGARA

• Main Author: Istiana
• Format: Theses
• Language: Indonesia
• Online Access: https://digilib.itb.ac.id/gdl/view/40263
• Institution: Institut Teknologi Bandung

The Eastern Indonesia area is strongly influenced by the monsoon climate change. Rainfall in this area is largely controlled by the Australian - Indonesian Summer Monsoon intensity, which is one of the largest monsoon systems on Earth. Previous researchers found that pollen and spores of marine sediments in the eastern part of Indonesia were able to reflect glacial climates - interglacial conditions, but still not detailed on climate events during Pleistocene-Holocene period. Therefore, it is important to do some research that can determine the changes on the distribution and characteristics of pollen due to climate change in the Sumba Sea since the Late Pleistocene. Palinological analysis, elements content, grain size, and 14C radiocarbon dating were carried out on the ST08 drill core in Sumba Sea. These analyses provide characteristics of pollen distribution due to climate change since 18,255 BP. These analyses also show that the percentage of Gramineae increases (75%) during glacial period, indicates a cooler and drier climate. At the same period, mangrove pollen (4%) percentage shows low value. Interglacial periods are characterized by high values percentages of pteridophyte (200%) and tropical lowland taxa (42%). Based on palynomorph characteristics that supported by sediment characteristics, several climate events during the glacial period of about 18.255 BP can be identified including: Last Glacial Maximum (LGM), Oldest Dryas, Interstadial Bølling, Older Dryas, Allerød interstadial, and Younger Dryas. Entering the Holocene around 10.904 BP climate events that can be identified including Holocene Tropical Climate/HTC 6, HTC-5, Top Cooling, HTC- 4 (Holocene Maximum), HTC-3, HTC-2, HTC-1, Medieval Warm Period, and the Little Ice Age. During the glacial periods, climatic conditions in study area are more influenced by the southeast monsoon. These conditions are indicated from the low rainfall at these periodes, whereas during the interglacial periods the intensity of the northwest monsoon has increase with the increasing rainfall.