Severe drought pushed Polynesian sailors across the Pacific Ocean

Researchers have linked a major environmental crisis to the rapid expansion of Polynesian seafaring communities across the Pacific Ocean.

Scientists from the University of Southampton and the University of East Anglia believe that a prolonged period of drought forced these populations to migrate toward wetter islands to the east.

The study focuses on a period known as the Long Pause, during which Polynesian expansion across the ocean appeared to stop for about 1,700 years after ancestors reached Samoa and Tonga approximately 3,000 years ago. Between 900 and 1050 AD, this migration resumed abruptly. Within roughly 250 years, voyagers settled on islands including Tahiti and Hawaii, eventually reaching continental America. The research team analyzed ancient mud buried in swamps and lakes in Samoa, Tonga, French Polynesia, and the Cook Islands.

Dr. Mark Piapl conducted geochemical analysis on chemical traces left by freshwater algae and leaves. The results showed that Samoa and Tonga experienced their driest conditions in 2,000 years just as the migration began. Simultaneously, climate modeling by Manoj Joshi showed that a tropical rain zone shifted eastward, making eastern islands wetter. David Siyar, a professor at the University of Southampton, states that the lack of water and food availability created strong motives for people to seek new opportunities.

Other factors likely included population growth and improved boat technology, such as moving from U-shaped hulls to V-shaped hulls with better sail systems. These advancements allowed sailors to navigate against prevailing winds.