(HOST) Vermont schools’ February vacation is upon us, and many of us dream of warm beaches. Commentator Peter Gilbert thinks of Hawaii and tells us about dramatic developments in understanding Hawaii’s prehistory – the time before there were written records.
(GILBERT) Oral histories of Hawaii were first written down in the 1800s. Those ancient stories tell of a powerful ruler named Pi’ilani, who defeated chieftains on the island of Maui, married a powerful chieftess and became absolute ruler. Sounds like an archetypal story. If you count the generations of “who begat whom” in the oral history, this king should have ruled about 1570 to 1600.
In fact, that oral history may be stunningly accurate. Recently, archaeologist Patrick Kirch of the University of California Berkeley and geochronologist Warren Sharp teamed up to try to determine the age of the many ancient Hawaiian temples on Maui. A description of their report appears in the January 7 edition of the journal Science. Geochronologist Sharp specializes in dating old coral reefs that are now above sea level; their age tells us how ocean levels have changed over time.
Hawaiian temples, or heiaus, were made largely of wood and thatch. All that remains is their foundations and the base of their rock walls – rock-wall outlines, some about the same height as stone walls you find in Vermont. Unlike New England stone walls, the heiau walls are made, not of field stone or broken granite bedrock, but of black lava rock.
To determine the age of the heiaus, Kirsh and Sharp studied pieces of branch coral that had been placed into the temple foundations, presumably as offerings. Because the fine and beautiful details on the coral pieces remain, the researchers conclude that the pieces were broken off fresh from living coral reefs and not, say, gathered, old and eroded, from the beach. Scientists know that coral takes uranium from sea water into their skeletons, and they know the rate that it decays from uranium to thorium. By looking at the ratio of uranium to thorium in the coral pieces, they can tell how long ago they were cut from the living coral reef.
And when was the coral they found in the temple walls cut from living coral? During a thirty-year period just about the year 1600. Through these researchers’ creative work, the humanities and science (archaeology and geology) combine to let the heiaus’ silent stones tell their story. What story does that date tell us? First, it suggests that there was, in fact, a single ruler who consolidated power at about that time, as the Hawaiian oral history said, because only a powerful ruler would have had the authority and excess labor to build so many temples so quickly.
More generally, it reminds us that, often, there’s not only great truth, but also remarkable accuracy in oral history – whether it’s from Polynesia, Native America, Africa or rural Vermont.
This is Peter Gilbert in Montpelier.
Peter Gilbert is the executive director of the Vermont Humanities Council. He spoke from our studio in Montpelier.