Major volcanic activity on the planet Mercury was ended about 3.5 billion years ago, according to a new research from a team of scientists lead by a planetary geologist. The study states that there aren’t any major volcanic eruptions on the surface of Mercury since millions of years.
The findings by NC State assistant professor and planetary geologist Paul Byrne and colleagues, studied the planet Mercury’s geological evolution in particular, and tried to find the results when rocky planets cool and contract in general.
The lead author of the study Paul Byrne said:
“There is a huge geological difference between Mercury and Earth, Mars or Venus. Mercury has a much smaller mantle, where radioactive decay produces heat, than those other planets, and so it lost its heat much earlier. As a result, Mercury began to contract, and the crust essentially sealed off any conduits by which magma could reach the surface.”
There are two common types of volcanic activities – explosive volcanism and effusive volcanism. In the first activity, the eruption of the volcano is more violent and it blasts ash and debris to more areas over larger areas. In the latter volcanic activity, the volcano erupts slowly and steadily spreads the lava flow out of the core area over the landscapes, which is believed as a key process in the formation of any planet’s crusts.
Effusive volcanism always helped researchers to learn about the geological history of many planets. Some examples are: From a study, scientists proved that an effusive volcanism was active on Mars a few million years ago, Venus witnessed it a few hundred million years ago and on Earth, it still takes place in many places. Have you seen photographers taking pictures near slowly flowing lavas?
Until now, the duration of effusive volcanic activity on Mercury, made of the same materials as these other planets, had not been known. The researchers from North Carolina State University used the Mercury’s surface images from NASA’s MESSENGER spacecraft to determine the period of the bulk of crust-forming volcanism on the planet.
They used a different technique to analyze the volcanism as there are no physical samples available from Mercury for radiometric dating. Researchers calculated absolute ages for these activities on the planet by using the images. They analyzed the number of craters and its size and placed it into the established mathematical models to determine that “the major volcanic activity on a planet – effusive volcanism” ended on Mercury about 3.5 billion years ago.
“These new results validate 40-year-old predictions about global cooling and contraction shutting off volcanism,” Byrne continues. “Now that we can account for observations of the volcanic and tectonic properties of Mercury, we have a consistent story for its geological formation and evolution, as well as new insight into what happens when planetary bodies cool and contract.”
The research was published in Geophysical Research Letters, with co-authors from the Carnegie Institution of Washington, Mount Holyoke College, the University of Georgia, Southwest Research Institute and Brown University.
[ Image credit: NASA ]