Benjamin Thompson

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746 appearances 10 recordings 1 series first heard Jul 2026 last heard 2 Sep

Benjamin Thompson’s voice in public audio — every appearance, attributed to the second.

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Recordings per month over the last 12 months — 10 in all, peaking in Jul 2026 with 5.

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Nature Podcast · Earthworks spotted in the Amazon hint at huge ancient civilization · 29 Jul 2026 podcast

And I'm Benjamin Thompson. matched

For our first story this week, we're heading over to the southwest corner of the Amazon to hear about the discovery of a lot of ancient human activity that's long been hidden from view. matched

Specifically, we're heading to an area in what is now the Brazilian states of Acre and Amazonas, close to where the borders of Brazil, Peru and Bolivia meet. matched

Between around seven hundred BC to nine hundred AD, this area was home to people who researchers are now calling the Arab. matched

This is Marty Parsonan from the University of Helsinki in Finland, who's been studying this region and the Akiri civilization for many years. matched

The Acary were prolific builders, and previous work has uncovered over a thousand earthworks, large structures comprising of mounds and troughs of dirt that can be several meters tall or deep. matched

These often form roads and geoglyphs, giant geometric shapes, often many hectares in size. matched

Some of these ancient earthworks are estimated to date back perhaps two thousand years before the European conquest of the fifteen hundreds. matched

And they're not just next to rivers and waterways, they're spread out. matched

Now, exactly what these structures were used for is unknown, but evidence points to them being important administrative and socio-cultural centers. matched

This week Marti and his colleagues have uncovered many more previously hidden structures, and they've used this information to estimate how many there might be in the area. matched

And it's a big number. matched

Many of the previously identified earthworks were found using aerial photography or satellite imagery, mostly in deforested areas, but that could only take the search so far. matched

LIDAR systems fire rapid pulses of laser light at a target and measure how long they take to bounce back, enabling the system to build up a 3D map of the object being looked at. matched

In the forest, some of the lasers find gaps in the canopy and reach the ground before bouncing back, allowing a topographic picture beneath the forest to be built up. matched

In fact, plane based lidar systems have been used in the Amazon before to detect structures hidden beneath the trees. matched

This is what Marti and his colleagues did, conducting surveys in Acri and Amazon states totaling about four and a half thousand square kilometers. matched

They found a bunch of previously unseen earthworks. matched

And while the team found a lot of earthworks covered by trees, they also found a lot in clearings that had been missed in satellite imagery, perhaps because they were too covered up with grass. matched

And the team put a range on when these newly identified structures might have been made. matched

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