According to a new study of cliffs on Mercury's surface, earthquakes, or "Mercuryquakes," may still occur. The finding was made by analyzing the pattern which marks where rocks have been scoured away by water.
These patterns can be seen on many planetary bodies, including Earth and its moon. But because Mercury has no atmosphere to speak of, its magnetic field keeps charged particles away from its surface, which would otherwise mask earthquake activity. This makes Mercury the first known example of an Earth-like planet that might harbor life capable of causing earthquakes.
Earthquakes are caused by shifts in mass within the earth's crust. These shifts may be due to changes deep within the planet's interior, such as rising or falling temperatures or pressures, or they may result from movements between different layers of rock that make up the earth's surface. The most powerful earthquakes on record occurred about 90 million years ago when giant plates carrying continental fragments slid against each other, creating seismic waves that were recorded by scientists on Earth today.
This refers to the effect that sudden drops in air pressure have on fluids inside objects such as bottles or humans.
Shake, shake, shake! Earthquakes may occur on Mercury. The hills of Mercury are rife with earthquakes, according to a research published Monday in Nature Geoscience. The tiny planet joins Earth as the Solar System's only other known tectonically active planet. Scientists have suspected seismic activity on Mercury since 1877, when astronomers first noticed changes in its orbit.
They reached this conclusion after studying data from NASA's Mariner 10 spacecraft, which passed by Mercury in 1974 and 1992. During these flybys, scientists used radar to measure surface features below 40 miles (64 kilometers) deep. They found that while some areas changed shape or position relative to each other, others appeared to slide past one another like moving maps of the same region. This behavior is typical of planets with strong surfaces that deform under their own weight.
The seismic activity on Mercury appears to be very low-frequency oscillation, or LFOS, which means that most of the time there is no noticeable movement but occasionally there is an earthquake. The study estimates that the average rate of earthquake occurrence is one per month, but some months will have more events than others. In addition, there appear to be two types of earthquakes: long, drawn-out events with slow motion at the end; and short, sharp shocks without any visible effects afterward.
Mercury, which is considerably smaller than Earth, does not have tectonic plates (plural)—it just has one. Despite this geological oneness, the surface of the rock has linear characteristics generated by compressing. Without clashing tectonic plates to supply the squeezing, another process is required. As a result, most of the surface of Mercury is slowly stretched like a rubber band.
This picture was taken by the MESSENGER spacecraft and shows many large craters formed by impacts from space debris. These impacts create a nearly constant stress on the planet's crust that stretches it like a rubber band until it reaches its limit and creates more craters. As MESSENGER approaches Mercury, this continuous creation and destruction of craters will allow scientists to learn about the history of the planet's surface over time.
There are two ways in which Mercury's lack of tectonic plates could be relevant to astrobiology. The first is that if a planet lacks active tectonics, that means there may be no volcanic activity to destroy harmful biological molecules. The second is that because there are no continental drift or plate collision events, there is no way for living organisms to migrate to different regions of the planet's surface.
It has been suggested that viruses might be able to survive such long periods without changing hosts that they would also be found on other planets that do not have life as we know it today.
A marsquake is a quake that, like an earthquake, causes a shaking of the surface or interior of Mars as a result of a rapid release of energy in the planet's interior, such as plate tectonics, from which most quakes on Earth originate, or maybe from hotspots such as Olympus Mons... However, since Mars has no atmosphere to dissipate energy, marsquakes are much more violent than those on Earth. The largest recorded marsquake was estimated to have had a magnitude of 7.5. It occurred near the Martian South Pole in 1990 and measured several miles in length.
Earth's largest earthquake, the 9/11 tsunami, was only about 6 miles long. By comparison, the largest known marsquake was almost 20 miles long.
The strongest earthquake ever recorded on Earth happened in Chile in 1960. Its magnitude was 8.5. No one knows exactly how strong a marsquake has to be to destroy parts of it, but based on what we know now, it must have been at least 7 on the Richter scale.
In conclusion, marsquakes are similar to earthquakes in general terms. They occur when part of Mars' surface moves relative to another part. But since Mars has no atmosphere to dissipate energy, marsquakes are more violent than those on Earth. The largest known marsquake was almost 20 miles long.