A new study has shed light on the mystery behind an ancient thriving civilization that vanished around 3,600 years ago.
The Indus Valley civilization, also known as the Harappan civilization, flourished in its mature form in the northwestern regions of South Asia during the Bronze Age from approximately 2600 BCE to 1900 BCE.
Considered to be highly developed, the civilization was spread across the Indus River basin, covering parts of modern-day Pakistan, India and Afghanistan.
Despite its remarkable achievements, much about the Indus Valley civilization remains a mystery, including its social and political structures, language and the reasons behind its decline and disappearance. Its written language, which has yet to be deciphered, has made its history and culture difficult to fully understand.
It has been posited by several experts that a drought hit the Indus Valley around 4,200 years ago, although its magnitude has yet to be determined.
The recent study, published in the peer-reviewed journal Communications Earth & Environment on April 4, claims that a stalagmite found inside Dharamjali Cave in the Himalayas paints a detailed image of life in the ancient civilization.
The cave is situated about 290 miles northeast of New Delhi and in the Indian Himalayan region of Uttarakhand.
Scientists were able to reconstruct historic rainfall patterns as far back as 4,200 years ago using mineral deposits extracted from the stalagmite.
According to the researchers, they have concluded that instead of a “single megadrought that lasted about 100–200 years,” there were “three major dry periods” between 4,200 and 3,900 years ago with each period having lasted “25–90 years.”
As water for necessary crops became less available, massive Indus cities, including Harappa, dropped in population as people moved to “smaller and more flexible rural settlements.”
The researchers also pointed to a drop in “craft activities and innovation in Indus urban centers… [and] long-distance exchange and trade.”
“The archaeological evidence indicates that over a 200-year period, the ancient inhabitants took various steps to adapt and remain sustainable in the face of this new normal,” noted the study’s lead author, Alena Giesche, who conducted the research while pursuing her Ph.D. at the University of Cambridge.
According to the study, the Indus Valley civilization completely vanished around 3,600 years ago — about 300 years following the final dry period.