Home / Science / Io's largest volcano, Loki, erupts every 500 days. Every day now it will erupt again.

Io's largest volcano, Loki, erupts every 500 days. Every day now it will erupt again.



Jupiter's moon Io is in sharp contrast to the other three Galilean moons. While Callisto, Ganymede and Europe all seem to have oceans below the ground, Io is a volcanic world covered with more than 400 active volcanoes. Io is actually the most volcanically active body in the solar system.

Io's largest volcano is called Loki, after a god in Norse mythology. It is the most active and powerful volcano in the solar system. Since 1979 we have known that it is active and that it is both continuous and variable. And since 2002, thanks to a research paper in Geophysical Research Letters, we have known that it breaks out regularly.

The first author in the 2002 paper was Julie Rathbun, who is now a senior scientist at the Planetary Science Institute. Now Rathbun has presented a poster about Loki at the American Astronomical Society's 51

st Annual Meeting of the Planetary Sciences Department. According to Rathbun, Loki is due to erupt again every day now.

"If this behavior remains the same, Loki would erupt in September 2019 …"

Julie Rathbun, PLANETARY BUSINESS INSTITUTE

Loki is large enough for Earth-based telescopes to see it. On the poster, Rathbun and the other author say J.R. Spencer said that between 1988 and 2000, Loki interrupted every 540 days. During about half of these days, Loki was light, while the other half Loki was darker in size. During the decade thereafter, observations were rare and there did not appear to be any periodicity for Loki's operations.

However, from 2013, Loki again showed periodicity. This time, there appeared outbreaks every 475 days for 160 days. What does all this mean?

<img src = "https://www.universetoday.com/wp-content/uploads/2019/09/782px-Loki_Patera_Color_Voyager.jpg" alt = "A Voyager 1 image mosaic by Loki and the surrounding surface of Io , including lava flows and volcanic pits. There are many volcanic caldera and lava flows. Loki Patera, an active lava lake, is the large shield-shaped black feature. Image Credit: By NASA / JPL / USGS – http://photojournal.jpl.nasa.gov/ catalog / PIA00320, Public Domain, https://commons.wikimedia.org/w/index.php?curid=4898984 [19659009] A Voyager 1 image mosaic of Loki and the surrounding surface of Io, including lava flows and volcanic pits. There are many volcanic caldera and lava flows. Loki Patera, an active lava lake, is the large shield-shaped black feature Image Credit: By NASA / JPL / USGS – http://photojournal.jpl.nasa.gov/catalog/PIA00320, Public Domain, https : //commons.wikimedia.org/w/index.php? curid = 4898984 [19659010] In a press release from the Planetary Science Institute, R said athbun: “If this behavior remains the same, Loki should break out in September 2019, at about the same time as the EPSC-DPS meeting in Geneva. We correctly predicted that the last outbreak would occur in May 2018, "said Rathbun, who presented his poster" Ios Loki Volcano: An Explanation of its Tricky Behavior and Prediction for the Next Outbreak "on September 17 at the Planetary Department of the American Astronomical Society Annual Meeting 51 in Geneva, Switzerland.

If Loki breaks out when Rathbun predicts it, it should be a pretty impressive scientific prediction. Volcanoes are hard to predict in themselves. There are many variables to a volcano, and of course much of what drives a volcano's behavior is hidden underground.

 One of many volcanic eruptions that regularly happens on Io, the most volcanically active body in the solar system. Io is heated by tidal interactions with Jupiter, which presses the moon and warms it. Image credit: NASA / JPL / University of Arizona
One of many volcanic eruptions that regularly occur on Io, the most volcanically active body in the solar system. Io is heated by tidal interactions with Jupiter, which presses the moon and warms it. Image credit: NASA / JPL / University of Arizona

All this is true for Loki, plus, it is also on a moon orbiting a planet nearly a billion miles away, which is the furthest.

“Volcanoes are so hard to predict because they are so complicated. Many things affect volcanic eruptions, including the rate of magma supply, the composition of magma – especially the presence of bubbles in the magma, the type of rock the volcano sits in, the fracture state of the rock, and many other issues, "Sa Rathbun.

Rathbun believes that Loki's size contributes to its predictability. Basic physics can overwhelm some of the minor factors she mentions.

 Ios surface is marked by volcanic features and rocks. This Voyager 1 mosaic covers Io's southern polar region. At the bottom of the picture is Haemus Mons, 1 10 km. high mountain. The rest of the image is typical of Io, with flat volcanic plains, eroded volcanic plateaus and cratered volcanic calderas. Image Credit: By NASA / Jet Propulsion Laboratory / USGS - http://photojournal.jpl.nasa.gov/catalog/PIA00327, Public Domain, https://commons.wikimedia.org/w/index.php?curid=18530344 [19659017] Ios surface is marked by volcanic features and rocks. This Voyager 1 mosaic covers Io's southern polar region. At the bottom of the picture is Haemus Mons, 1 10 km. high mountain. The rest of the image is typical of Io, with flat volcanic plains, eroded volcanic plateaus and cratered volcanic calderas. Image Credit: By NASA / Jet Propulsion Laboratory / USGS - http://photojournal.jpl.nasa.gov/catalog/PIA00327, Public Domain, https://commons.wikimedia.org/w/index.php?curid=18530344 [19659013] "We believe that Loki can be predictable because it is so big. Because of its size, basic physics are likely to dominate as it erupts, so the small complications affecting smaller volcanoes are unlikely to affect Loki as much, ”Rathbun said. </p>
<p>  "But," Rathbun said, "You have to be careful because Loki is named after a trickster god and the volcano has not been known to behave itself. In the early 2000s, when the 540-day pattern was discovered, Loki's behavior changed and did not exhibit periodic behavior again until around 2013. "</p>
<figure class=
The brightness of light as a function of time from various sources, including Keck and Gemini Telescope. The upper panel shows the total available time history while the bottom is only the last 5 years. the background is the original period of 540 days.The vertical line 2018 is mid-May 2018, which indicates our prediction for when the last outbreak began. Image credit: Rathbun et al., 2019.

Loki, also called Loki Patera, It's massive. It's 202 kilometers (126 mi) in diameter. It's actually a type of feature called a lava lake, a depression partially filled with molten rock, with a thin solid crust It is directly connected to a reservoir reservoir under it.

 Yoytan is covered with dark, collapsed volcanoes. Image credit: NASA / JPL / USGS
Yoytan is covered with dark, collapsed volcanoes. Image credit: NASA / JPL / USGS

In their poster, Rathbun and Spencer say that Loki's changed periodicity may be due to a rolling crust. When it erupts, magma from the reservoir under lava spreads out over the lake's surface at a rate of about 1 kilometer per day. When the lava cools, it solidifies and forms a new solid crust. Eventually, the crust becomes unstable, triggering a new eruption and restarting the sequence. The change in periodicity may be due to changes in the porosity of the lava, making each new crust more or less stable.

At the moment it is just a model, but it is good that explains Loki Patera's changing periodicity. If it breaks out in the next few days, as Rathbun and Spencer predict, the model will be so much stronger.

More:


Source link