Mars Exploration News  
MARSDAILY
Island in a lake of lava - the Martian volcano Jovis Tholus
by Staff Writers
Berlin, Germany (SPX) Jan 27, 2022

Oblique perspective view of 'Jupiter's Dome'

These images, created using data acquired by the High Resolution Stereo Camera (HRSC) on board ESA's Mars Express orbiter, show the Jovis Tholus volcano and various other landscape features, such as tectonic faults, impact craters and solidified lava flows, in the Tharsis region of Mars. The Tharsis uplift, which is several kilometres high, was one of the most active volcanic regions near the Martian equator. With a diameter of almost 4000 kilometres, this plateau is almost as large as Europe. Most Martian volcanoes are located here, in particular four of the volcanic giants, with heights between 14 and 24 kilometres.

The HRSC was developed by the German Aerospace Center and is operated by its Institute of Planetary Research in Berlin-Adlershof. Since 2004, it has been mapping Mars in high resolution, in three dimensions and in colour; it is carried on board ESA's Mars Express orbiter. The data acquired by HRSC an important resource for current and future Mars research. The findings already obtained in the course of the mission have greatly changed researcher's theories about the geological evolution of the Red Planet.

Jovis Tholus (Latin - 'the dome of Jupiter') is a shield volcano. This type of volcano is formed by fluid, low-viscosity lava flows, creating an extensive cone with a shallow slope that resembles a flat shield. The lava is comparable to that ejected in 2021 by the Cumbre Vieja volcano on the island of La Palma in the Canary Islands. With a height of 17 kilometres (measuring from its submarine base to the summit), the largest shield volcano on Earth is Mauna Loa in Hawaii. Its counterpart on Mars is Olympus Mons, which rises 24 kilometres above the Tharsis uplift and is the largest known volcano in the Solar System.

Long period of volcanic activity
The comparatively small, 1500-metre-tall shield volcano Jovis Tholus lies, in a sense, in the 'shadow' of Olympus Mons, halfway between its 5000 to 6000-metre-high eastern escarpments and the 18-kilometre-high volcano Ascraeus Mons, the northernmost of the three shield volcanoes collectively referred to as the Tharsis Montes.

Jovis Tholus is located on the northern edge of an extensive lava plain, southeast of the Ceraunius Fossae graben system and northeast of the Ulysses Fossae graben system. The striking Jovis Tholus uplift has a diameter of 58 kilometres, similar in size to the island of Gran Canaria. Its caldera, which is comparatively large at 28 kilometres across, consists of a total of five craters, which suggests a long period of volcanic activity. The individual calderas are interconnected, the younger ones each having a slightly lower floor, which shows that the ceilings of the magma chambers that used to be below them have collapsed deeper and deeper.

Like most shield volcanoes, 'Jupiter's Dome' is surrounded by younger lava flows. They obscure many of the original landscape features - not even a crater rim is visible - and are therefore probably several hundred metres thick, like a 'stone lake'. They also cover a series of channels in the immediate vicinity of the volcano. Its eastern volcanic flank forms the steep rock face of a graben that continues northwards from there. Some parts of this graben can also be seen many kilometres further north in the plains.

On closer inspection, the outlines of many individual lava flows can be seen on the lava surfaces. They consist of solidified basalt lava, which has a very low content of silicate minerals and water. Therefore, this lava is very inviscid, non-explosive and can flow or be displaced very far into the plain by the 'lava supply' - even on very shallow slopes - before solidifying.

A very interesting structure is located about 30 kilometres east of the volcano's flank. A second, less developed volcano rises here. It is best recognised in the topographical colour view in the lower right half of the image. Here, less fluid, more viscous lava probably emerged from a fissure. Such fissure volcanoes exist on Earth, for example in Iceland and Hawaii.

A 'muddy' impact
But these images reveal more than just volcanic structures. About 60 kilometres north of Jovis Tholus is an impact crater, 30 kilometres in diameter, whose ejecta blanket has a special form. Its morphology suggests that the ejecta had a rather fluid consistency and was distributed around the crater depression like mud that was 'mobilised' in a way similar to a pool into which stones have been thrown and deposited in a similar form; this is referred to as 'fluidised ejecta'. To form such a layer of ejecta, water or ice must have been present in the subsurface, which was liquefied or vaporised during the impact.

In addition, several outflow channels with separate strata that are 0.5 to 3.4 kilometres wide originate directly on the northwestern edge of the sharp graben that bounds the impact crater (and appears to cut through the upper left corner of the images as if created with a knife). Water was apparently released there in surges, forming streamlined islands and terraced channel walls. Several much smaller channels run through the northern ejecta blanket of the large impact crater. Researchers suspect that these large amounts of water were released by a pressurised aquifer while the faults were forming, or that volcanic heating caused the ground ice to melt, and the water then took the easiest route through the gully system to the surface.


Related Links
High Resolution Stereo Camera
Mars News and Information at MarsDaily.com
Lunar Dreams and more


Thanks for being here;
We need your help. The SpaceDaily news network continues to grow but revenues have never been harder to maintain.

With the rise of Ad Blockers, and Facebook - our traditional revenue sources via quality network advertising continues to decline. And unlike so many other news sites, we don't have a paywall - with those annoying usernames and passwords.

Our news coverage takes time and effort to publish 365 days a year.

If you find our news sites informative and useful then please consider becoming a regular supporter or for now make a one off contribution.
SpaceDaily Contributor
$5 Billed Once


credit card or paypal
SpaceDaily Monthly Supporter
$5 Billed Monthly


paypal only


MARSDAILY
Creating chaos: Craters and collapse on Mars
Paris (ESA) Nov 22, 2020
Elevation can be deceiving in satellite imagery of Mars, even when differences are extreme - as demonstrated by this image of Pyrrhae Regio from ESA's Mars Express. A chunk of terrain has collapsed and dropped more than four kilometres below its surroundings, illustrating the incredible contrast and dynamism seen across the martian surface. This slice of Mars, seen here as imaged by Mars Express' High Resolution Stereo Camera (HRSC), shows signs of various intriguing processes. A scattering ... read more

Comment using your Disqus, Facebook, Google or Twitter login.



Share this article via these popular social media networks
del.icio.usdel.icio.us DiggDigg RedditReddit GoogleGoogle

MARSDAILY
NASA's HERMES mission passes key milestone, moves toward launch

China, Russia to start building lunar research station by 2026

A VIPER in the Sand

Israel Signs Artemis Accords

MARSDAILY
China Focus: China to explore lunar polar regions, mulling human landing: white paper

China to boost satellite services, space technology application: white paper

China Focus: China to explore space science more: white paper

China to improve space debris monitoring: white paper

MARSDAILY
Why are comet heads green - but not their tails?

NASA asteroid tracking system now capable of full sky search

Solar Orbiter catches a second comet by the tail

Looking Up at the Asteroids in the Neighborhood

MARSDAILY
Oxygen ions in Jupiter's innermost radiation belts

Ocean Physics Explain Cyclones on Jupiter

Looking Back, Looking Forward To New Horizons

Testing radar to peer into Jupiter's moons

MARSDAILY
SwRI scientist uncovers evidence for an internal ocean in small Saturn moon

MARSDAILY
Satellogic completes transaction to become publicly traded company

China launches L-SAR 01A satellite for land observing

ESA supports the White House on greenhouse gas monitoring

Particles formed in boreal forests affect clouds in the troposphere

MARSDAILY
New ISS National Laboratory tool expands visibility of ISS-related educational resources

Caltech names Laurie Leshin Director of JPL

US issues visa to Russian ISS cosmonaut

NASA provides updated International Space Station Transition Plan

MARSDAILY
Exoplanet has Earth-like layered atmosphere made of titanium gas

Extreme exoplanet has a complex and exotic atmosphere

What the rise of oxygen on early Earth tells us about life on other planets

A planetary dynamical crime scene at 14 Herculis









The content herein, unless otherwise known to be public domain, are Copyright 1995-2024 - Space Media Network. All websites are published in Australia and are solely subject to Australian law and governed by Fair Use principals for news reporting and research purposes. AFP, UPI and IANS news wire stories are copyright Agence France-Presse, United Press International and Indo-Asia News Service. ESA news reports are copyright European Space Agency. All NASA sourced material is public domain. Additional copyrights may apply in whole or part to other bona fide parties. All articles labeled "by Staff Writers" include reports supplied to Space Media Network by industry news wires, PR agencies, corporate press officers and the like. Such articles are individually curated and edited by Space Media Network staff on the basis of the report's information value to our industry and professional readership. Advertising does not imply endorsement, agreement or approval of any opinions, statements or information provided by Space Media Network on any Web page published or hosted by Space Media Network. General Data Protection Regulation (GDPR) Statement Our advertisers use various cookies and the like to deliver the best ad banner available at one time. All network advertising suppliers have GDPR policies (Legitimate Interest) that conform with EU regulations for data collection. By using our websites you consent to cookie based advertising. If you do not agree with this then you must stop using the websites from May 25, 2018. Privacy Statement. Additional information can be found here at About Us.