Dating Volcanic Eruptions on Venus
(Note: Look for updates on Merapi and Kliuchevskoi later today)
I caught an article over the weekend about the potential of recent volcanism on Venus. The study that appeared Geophysical Research Letters found that some flows on the surface of Venus are, in fact, still warm enough to be recognized as, well, warmer than the surrounding surface (see upper left - click on image to see a larger version). Dr. Nataliya Bondarenko and her colleagues looked at microwave data from the Magellan mission during the 1990s - and using this data, relative and absolute heat flow on the surface can be compared. A few of the flows on the Bereghinia Planitia (see below) appear to be much warmer than the surrounding - up to 85C above the the expected temperature.
Image of the Bereghinia Planitia on Venus, a potential location of recent volcanism on Venus.
So, why is this interesting? Well, remember, after lava erupts, it cools, but not instaneously. The residual heat from the lava (magma) takes time to dissipate - entirely through conduction. This means that if there is anomalously high temperatures recorded on features that look like lava flows, this would suggest that the flows could be geologically recent. Bondarenko suggests that the heat measured on these flows on Venus could mean that they are less than a century old, otherwise the flows would not have appeared "hot" to the Magellan microwave instruments. The flow is at least 15 years old as it was imaged by Pioneer Venus in 1978, but this could means that the flow is anywhere from 15-100 years old, making it the youngest extraterrestrial silicate magmatism in the solar system.
There have been other studies on the age of lava flows on Venus. A paper in Science by Suzanne Smrekar and others looked at the ages of flows in the southern hemisphere of Venus. They used geomorphic criteria - the extent of weathering on the flows - to determine potential ages. They found that the flows are no less than 2.5 million years old, but likely closer to 250,000 years or less rather than the centuries old that Bondarenko found.
Beyond this, there is little other corroborating evidence for volcanic activity on Venus. Last year, there was some interesting anomalies in the atmosphere of Venus (discovered by an amateur astronomer) that could be interpreted as a volcanic plume, but it was never substantiated as an eruption.
The surface of Venus imaged by Magellan radar.
The surface of Venus does obviously show evidence of geologically recent volcanism - the surface of Venus is covered with features such as lava flows, fissures and domes that likely formed within the last half a billion years based on the extent of cratering on the surface of the planet. In fact, there are some theories that suggest that the entire surface of Venus (see above) was formed during a catastrophic volcanic event that enveloped much of the surface about 300 million years ago and since then, only 4-6% of the surface has been resurfaced. However, much of the evidence of this is circumstantial and is not universally accepted. It is clear, though, that the volcanic activity on Venus is likely linked to the harsh climate of the planet.
Evidence of explosive volcanism on the surface of Venus.
The Magellan mission captured multitude of amazing images of the volcanic features on Venus, including the famous pancake domes and evidence for explosive eruptions (see above) on the surface as well. If any planet in the solar system is likely to have a silicate eruption in the (geologically) near future, it is the Earth's sister planet.
Malcolm Gladwell teaches "Get over yourself and get to work" for Big Think Edge.
- Learn to recognize failure and know the big difference between panicking and choking.
- At Big Think Edge, Malcolm Gladwell teaches how to check your inner critic and get clear on what failure is.
- Subscribe to Big Think Edge before we launch on March 30 to get 20% off monthly and annual memberships.
Can sensitive coral reefs survive another human generation?
- Coral reefs may not be able to survive another human decade because of the environmental stress we have placed on them, says author David Wallace-Wells. He posits that without meaningful changes to policies, the trend of them dying out, even in light of recent advances, will continue.
- The World Wildlife Fund says that 60 percent of all vertebrate mammals have died since just 1970. On top of this, recent studies suggest that insect populations may have fallen by as much as 75 percent over the last few decades.
- If it were not for our oceans, the planet would probably be already several degrees warmer than it is today due to the emissions we've expelled into the atmosphere.
Yes, a coup d'état.
- Though we know today that his policies eventually ended the Great Depression, FDR's election was seen as disastrous by some.
- A group of wealthy bankers decided to take things into their own hands; they plotted a coup against FDR, hoping to install a fascist dictator in its stead.
- Ultimately, the coup was brought to light by General Smedley Butler and squashed before it could get off the ground.
Michael Dowling, Northwell Health's CEO, believes we're entering the age of smart medicine.
- The United States health care system has much room for improvement, and big tech may be laying the foundation for those improvements.
- Technological progress in medicine is coming from two fronts: medical technology and information technology.
- As information technology develops, patients will become active participants in their health care, and value-based care may become a reality.
SMARTER FASTER trademarks owned by The Big Think, Inc. All rights reserved.