In our first piece for BBC Reel, we travel back to 4,000 BCE with Liviu Giosan, a geologist with the Woods Hole Oceanographic Institution. Dr. Giosan used an innovative combination of techniques – including radiocarbon dating, DNA sequencing, X-ray microscopy of deep sea sediment- to figure out what caused the ancient Harappan civilization to disappear from the Indus River Valley in present-day Pakistan.
Before pitching this story, we actually hadn’t been aware of the Harappans, but research shows that they had advanced cities, featuring sewer systems, communal pools, and standard geometric construction materials. They had a (as-yet undecipherable) written language, art, toys for children, and traded with the other large civilizations of the time in Mesopotamia and Egypt.
But one thing wasn’t so advanced: the Harappans relied on inundation agriculture to grow crops, meaning that they were very susceptible to changes in the monsoon rains that caused the Indus River to flood on schedule. Dr. Giosan determined that shifts in the seasonal monsoons put the Harappans’ food supply at risk, prompting them to migrate to the foothills of the Himalaya where rain was more regular. Alas, the focus on survival disrupted their thriving culture, and by 1800 BCE the Harappans were no longer living in large cities and had abandoned their writing and art.
Although we have much still to learn about this fascinating ancient culture, their fate perhaps has a message for us in modern times.
It was a pleasure to work with our editors at BBC, as well as Dr. Giosan and his colleagues at the National Ocean Sciences Accelerator Mass Spectrometry (NOSAMS) facility at WHOI!
