East Micronesia (49,293 – 28,578 BCE): Upper…

East Micronesia (49,293 – 28,578 BCE): Upper Pleistocene — Reef Platforms, Windward Rims, and Seabird Realms (No Human Presence)

Geographic & Environmental Context

East Melanesia includes Kiribati (Gilbert Islands), the Marshall Islands (Ralik and Ratak chains), Nauru (uplifted phosphatic limestone island), and Kosrae (high, volcanic island on the eastern Caroline arc).

• Sea level sat ~100 m below modern, exposing broad reef flats and terrace benches on the future Ralik–Ratak and Gilbert atolls; Nauru stood as a higher limestone mesa; Kosrae loomed as a steep volcanic high island with deep valleys.

Climate & Environmental Shifts

• Last Glacial Maximum: cooler SSTs, stronger trades and winter swell; slower coral accretion but wide intertidal zones.

Baseline Ecology

• Seabird supercolonies nested on outer cays; turtles used broad beaches; lagoonal microhabitats were incipient.

• Kosrae’s montane forest and unmodified streams sustained high freshwater biodiversity.

Long-Term Significance

These lowstand landscapes fixed the reef foundations and high-island watersheds that later support Micronesian arboriculture, taro pondfields, and lagoon fisheries.