Olympus Mons, on the planet Mars, is the largest volcano in our solar system. It’s larger than the U.S. state of Arizona. And it towers about 14 miles (22 km) above the encircling Martian desert. It’s a spectacular sight from Mars orbit. However now think about this big Mars volcano as an island surrounded by water. On July 25, 2023, researchers on the French Nationwide Centre for Scientific Analysis (CNRS) and Université Paris-Saclay in France announced the outcomes of their new examine suggesting that Olympus Mons was as soon as a volcanic island, surrounded by a deep sea.
On July 24, the researchers published their peer-reviewed findings within the journal Earth and Planetary Science Letters.
Largest volcano within the solar system
Olympus Mons isn’t simply massive. It’s large, and much past the dimensions of any volcano on Earth. It simply dwarfs Earth’s greatest volcano, Mauna Loa in Hawaii (which is 75 miles/ 120 km throughout and 5.6 miles/ 9 km tall).
In distinction, Olympus Mons is about 374 miles (600 km) broad broad at its widest level. And it stands about 14 miles (22 km) above the encircling plains (2 1/2 instances the peak of Everest).
The caldera at its summit is 53 miles (85 km) in diameter!
Olympus Mons is a shield volcano, and scientists stated it was doubtless constructed up from eruptions of pretty fluid (low viscosity) basaltic lava. Protect volcanoes have a decrease profile – wider than they’re tall – than different forms of volcanoes.
Was Olympus Mons a volcanic island?
Proof has been rising in recent times for an ancient ocean within the northern hemisphere of Mars. Scientists have even discovered indicators of former shorelines and marine sediments. Now, evidently an ocean could have surrounded Olympus Mons, that means that it was truly a volcanic island a couple of billion years in the past.
The brand new examine confirmed that Olympus Mons shares morphological similarities with many energetic volcanic islands on Earth. These embody ones like Pico Island in Portugal, Fogo Island in Canada and Hawaii in america. Geoscientist Anthony Hildenbrand at CNRS, who led the analysis workforce, stated:
Right here we present that the Olympus Mons big volcano shares morphological similarities with energetic volcanic islands on Earth, the place main constructional slope breaks systematically happen on the sea-air transition in response to sharp lava viscosity contrasts.
We suggest that the higher rim of the 6-kilometer [3.7-mi] excessive concentric important escarpment surrounding Olympus Mons more than likely shaped by lava flowing into liquid water when the edifice was an energetic volcanic island through the late Noachian–early Hesperian.
Thriller escarpment gives clues
One of many greatest clues in regards to the historical past of Olympus Mons is on the base of the volcano. The volcano doesn’t simply slope gently into the encircling terrain. As an alternative, for a lot of the circumference, the bottom is a steep cliff, or escarpment. This escarpment is about 4 miles (6.5 km) tall. That abrupt change within the form of the volcano has lengthy puzzled planetary scientists.
The researchers discovered that this escarpment is much like these on volcanic islands on Earth. These cliffs type when lava flows down the perimeters of the volcanoes and hits the encircling ocean water. This creates a change within the viscosity of the lava. The paper said:
This leads us to suggest that Olympus Mons was a former volcanic island surrounded by liquid water.
The typical peak of the principle escarpments suggests a 6-km-thick [3.7-mi-thick] column of liquid water initially surrounding the inferred volcanic island. That is greater than the typical depth of oceans on Earth, and twice the believable depth for an early Martian ocean [about 3.8 billion years ago] … However, the escarpment peak will not be inconsistent with a globally shallow ocean.
However why the disparity with the estimated ocean depth from earlier research? Principally, the scientists stated, there have been large plumes of lava under the place the volcanoes now sit. These plumes created the Tharsis Bulge that this group of volcanoes sits on. Nevertheless, the identical plumes additionally deformed the planet’s crust beneath the ocean a lot that it truly shifted the ocean itself.
The highest of the escarpment would have been the ocean stage of the now long-gone ocean. Scientists have additionally dated the final lava flows to about 3 to three.7 billion years in the past, so the ocean would have been current at the moment.
Comparable volcano a whole bunch of miles away from Olympus Mons
The researchers additionally discovered that one other volcano, Alba Mons, options comparable traits to Olympus Mons. Alba Mons is 932 miles (1,500 km) away, with huge lowlands separating it from Olympus Mons. This might imply that the ocean stuffed within the lowlands and surrounded each volcanoes. This helps earlier findings that the traditional ocean as soon as lined a lot of the northern hemisphere of Mars, within the lowlands. Because the paper explains:
Conspicuous slope breaks on the high of the principle basal escarpment surrounding Olympus Mons are right here interpreted as paleo-shorelines round a former volcanic island. Comparable options at Alba Mons additional help the existence of an early ocean occupying the northern plains of Mars alongside the northwestern fringe of the Tharsis area.
Apparently, a previous study from 2018 additionally prompt a hyperlink between the traditional ocean on Mars and the formation of the Tharsis volcano system, of which Olympus Mons is part.
Backside line: Scientists in France have discovered new proof that the biggest volcano on Mars, Olympus Mons, was as soon as a volcanic island surrounded by an historical northern ocean.
Source: A giant volcanic island in an early Martian Ocean?
Read more: Is Mars volcanically active?
Read more: Ancient ocean on Mars confirmed?
