MEJILLONES, Chile, March 18, 2022 (BSS/AFP) - When Chilean scientist
Osvaldo Ulloa led an expedition 8,000 meters under the sea to an area where
no human had ever been, his team discovered microscopic organisms that
generated more questions than answers.

   The January submarine expedition dove into the Atacama Trench, created by
the meeting of two tectonic plates in the eastern Pacific Ocean.

   "We pulled off the feat of taking humans into the trench where no other
human being had been before," Ulloa, the director of the Millennium Institute
of Oceanography at the University of Concepcion, told AFP.

   He was joined by American explorer Victor Vescovo and Millennium assistant
director Ruben Escribano on the 12-week journey off Chile's northern coast in
the 5,900-kilometer (3,650-mile) long trench that extends up to Ecuador.

   By the time the expedition, named Atacama Hadal, reached a depth of 100
meters it was already in pitch black darkness, with the crew members' vision
limited to what the submarine's powerful LED light could capture.

   Further down out of the darkness emerged remarkable examples of deep sea
life.

   "We came across geological structures and there we saw a type of
holothurians or translucent sea cucumbers, like jelly, that we had not
recorded and were most probably new species," said Ulloa.

   "We also discovered bacterial communities that had filaments that we did
not even know existed in the Atacama Trench and which feed on chemical and
inorganic compounds.

   "That opened up a huge number of questions: What are those compounds? What
type of bacteria are they? We have no idea, we're going to have to go back
there."

   The expedition also found species of amphipods, a type of crustacean
closely related to shrimp, which were scavenging crustaceans, segmented worms
and translucent fish. They were discovered in the same place in an unmanned
expedition in 2018.

   - 'Incredibly ambitious' -

   The Atacama Trench -- also known as the Peru-Chile Trench -- lies where
the Nazca and South American tectonic plates converge. It is an area that has
produced many earthquakes and tsunamis.

   "We will put three sensors on the South American Plate and two on the
Nazca Plate to see how the oceanic floor is deformed," said Ulloa.

   For the moment, "these types of sensors only exist on land."

   The devices will allow scientists to observe where energy is building in
areas that have not had an earthquake, thus helping predict where the next
temblor will take place.

   "It is an incredibly ambitious project," said Ulloa, adding that it is
"the largest experiment that has been done in underwater geology here in
Chile."

   The sensors are due to be placed during the second half of this year.

   "There is a lot of interest from the international community to put more
sensors in this region to study all the processes associated with the
collision of these two plates."