in the following picture, we will see a series of conical mounds. They each have a diameter of about 9 meters and a height of 2 to 4 meters.

doesn't seem like a big deal? But they are actually part of a huge "building complex". It is estimated that there are about 200m such mounds in southeastern Brazil, covering an area of 230000 square kilometers, which is almost the size of the whole of Britain. The mounds are arranged neatly and closely together like beehives, with each mound about 20 meters away from the six around it. The patterns of these mounds can even be seen in satellite photos-in fact, the number of them was calculated by the researchers using satellite photos of Google Maps.

Great things happen in our beautiful 1940s evening dresses. You'll be pleased with your sophisticated look.

(the mound seen by satellite photos. The picture is from the original paper.

these mounds all come from a local termites called Syntermes dirus, which are still active in the intricate underground nests beneath the mounds. The conical mound itself is not a nest for termites, there is no internal structure worth mentioning, and termites do not even use the top of the mound as a daily entrance and exit. Rather than "architecture", a more appropriate description is "garbage dump": termites simply pile up the soil dug up in underground nests to form such a large structure. The local dry and barren soil allows these mounds to be well preserved.

the construction of these mounds is a long process, and their history is even longer than we can imagine. The researchers sampled 11 mounds on the land. they collected soil particles at the center of the mounds and measured them by photoluminescence dating. Simply put, this method can measure when soil particles were last exposed to sunlight. The results show that the time for these soil particles to be buried in the mound varies from 690 to 3820 years, and rounded up to 4,000 years old. Given the large number of mounds, the researchers say that if more samples were taken, they should be able to find older parts.

there is very little research on these termites and the mounds they have piled up, and there are still many detailed questions that cannot be answered. But it is shocking to know that the huge structures built by termites can last for thousands of years and can be seen from satellites.

original paper: https://www.cell.com/current-biology/fulltext/S0960-9822(18)31287-9

related report: https://www.theatlantic.com/science/archive/2018/11/brazil-termite-murundus-mounds-space-4000-years-old/576160/

https://www.sciencedaily.com/releases/2018/11/181120073648.htm

(the original paper also has a video introduction, but there is no particularly good-looking picture. I won't put it here. )