Tag Archives: marsquake

Stunning animation shows how Marsquakes look like

The Earth has lots of earthquakes, but it’s not the only place with temblors. While Martian quakes are much smaller in intensity, they do exist — here’s how the seismic waves propagate through the planet:

Seismic waves from a marsquake as they move through different layers of the Martian interior. Credits: NASA/JPL-Caltech/ETH Zurich/Van Driel

Seeing the inside

When NASA sent astronauts to the moon in the Apollo 11 mission, they also had them deploy scientific instruments — including seismometers. But it took a couple more decades until the agency’s InSight lander brought the first seismometer to Mars in late 2018. Called the Seismic Experiment for Interior Structure (SEIS), the seismometer made history in April 2019, when it detected the first marsquake.

The mission is led by researchers at ETH Zurich in Switzerland who monitor and analyze the data. Because Mars doesn’t have active plate tectonics, it also has much fewer (and less intense) earthquakes. These temblors pose no realistic risk whatsoever — the purpose of the seismometer is to help researchers better understand the inside of the planet.

InSight’s seismometer has a cozy shelter on Mars. Credits: NASA.

Much of what we know about Earth’s internal structure also comes from seismology. When an earthquake occurs, it spreads out energy in the form of seismic waves. There are different types of waves which propagate differently through the Earth’s inside. By calculating the time of arrival between different types of waves, their amplitude, and several other parameters, seismologists make certain deductions about the Earth’s structure.

In a way, it’s a bit like how an ultrasound reading can reveal a baby inside a mother’s womb, except the scale and accuracy of the procedures is very different. Ultrasounds and seismic waves are both acoustic waves and they get similarly reflected and refracted. But researchers didn’t stop here.

Feeling a marsquake

Researchers at ETH took things even further: they wanted to see how a marsquake feels, compared to one on Earth or on the moon.

Of course, since the marsquake is much weaker than its earthly equivalent, the signal is also weaker. The team had to amplify the marsquake signals by a factor of 10 million in order to make the barely-perceptible tremors comparable to earthquakes. Moonquakes were similarly amplified.

The reason why quakes on different types of planets can feel differently is that they are affected by the material the waves pass through. We’re still in the very early days of studying marsquakes but so far at least, the results are encouraging.

The 2020 Mars Rover will also feature an instrument that will help researchers “see” beneath the Martian surface. The ground penetrating radar will use electromagnetic waves to create a high-resolution visualization of a Martian subsurface, at depths of up to 10 meters.

NASA detects first evidence of a Marsquake

Credit: Flickr, NASA.

On the 128th sol of the Martian lander Insight, researchers discovered a “Marsquake.” Scientists recorded the tremors with a French-made dome probe, the Seismic Experiment for Interior Structure (SEIS). While the event was too small to provide any useful information — if it had occurred on Earth, it wouldn’t have even registered — it was still the first quake recorded on Mars caused by forces inside the planet.

“We’ve been waiting months for our first marsquake,” said Dr. Philippe Lognonné, the Principle Investigator for SEIS. “It’s so exciting to finally have proof that Mars is still seismically active. We’re looking forward to sharing detailed results once we’ve studied it more and modeled our data.”

While Mars doesn’t have tectonic plates, which cause most of Earth’s quakes, both planets and the Moon experience the kind of quake caused by faults, or fractures in their crusts. As heavy masses and slow cooling add stress to the crust, it cracks, releasing energy.

Thousands of quakes were discovered on the Earth’s moon between 1969 and 1977 using five seismometers installed by Apollo astronauts.

“The Martian Sol 128 event is exciting because its size and longer duration fit the profile of moonquakes detected on the lunar surface during the Apollo missions,” said Lori Glaze, Planetary Science Division director at NASA Headquarters.

So far, the InSight team has yet to confirm the cause of the tremor, which was picked up on April 6. Three other signals, which occurred on March 14 (Sol 105), April 10 (Sol 132) and April 11 (Sol 133), could also be of seismic origin. The signals were far more enigmatic to the InSight team, but at least two of those do not appear to have been caused by wind or other unwanted sources of noise. Those signals were found to be much weaker than those on Sol 128 and were only detected by SEIS’s ultra-sensitive VBB sensors.

“InSight’s first readings carry on the science that began with NASA’s Apollo missions,” said InSight Principal Investigator Bruce Banerdt of NASA’s Jet Propulsion Laboratory (JPL) in Pasadena, California. “We’ve been collecting background noise up until now, but this first event officially kicks off a new field: Martian seismology!”