Tuff Schist

The adventures of an unstable geologist

17 notes

earthstory:

Limnic EruptionsLimnic Eruptions, also known as a lake overturn are very rare and are unlike the better known lava fountains or explosive eruptions typical of volcanoes. There have only been two reported cases of Limnic Eruptions; one in 1984 and the other in 1986.These types of eruptions are caused when large volumes of gas are trapped at the bottom of lakes, building pressure until it is released either by an earthquake, heavy storm or landslide. No damage occurs through fire, ash or smoke, but through the release of carbon dioxide. As CO2 is denser than air it causes the cloud to rush down the mountain suffocating everything in its path.Lake Nyos erupted over 80 million cubic metres of CO2 causing the death of 37 locals by burns and asphyxiation. The surrounding vegetation was flattened due to a tsunami around 5 metres high as a result of the sudden release of gas.A French team of scientists and engineers hypothesised possible solutions to reduce the amount of gas released in each Eruption. The team concluded that placing large plastic stacks in Lake Nyos would release the gas periodically; reducing the chance of another large scale Eruption. In 2001, permanent columns were placed to help release the gas as previous experiments were successful.-M.MSource/Further Reading: http://mivo-sys.tripod.com/limnic.htmlPhoto credit and source/further reading: http://suite101.com/article/1986-limnic-eruption-of-lake-nyos-a111515

earthstory:

Limnic Eruptions

Limnic Eruptions, also known as a lake overturn are very rare and are unlike the better known lava fountains or explosive eruptions typical of volcanoes. There have only been two reported cases of Limnic Eruptions; one in 1984 and the other in 1986.

These types of eruptions are caused when large volumes of gas are trapped at the bottom of lakes, building pressure until it is released either by an earthquake, heavy storm or landslide. No damage occurs through fire, ash or smoke, but through the release of carbon dioxide. As CO2 is denser than air it causes the cloud to rush down the mountain suffocating everything in its path.

Lake Nyos erupted over 80 million cubic metres of CO2 causing the death of 37 locals by burns and asphyxiation. The surrounding vegetation was flattened due to a tsunami around 5 metres high as a result of the sudden release of gas.

A French team of scientists and engineers hypothesised possible solutions to reduce the amount of gas released in each Eruption. The team concluded that placing large plastic stacks in Lake Nyos would release the gas periodically; reducing the chance of another large scale Eruption. In 2001, permanent columns were placed to help release the gas as previous experiments were successful.

-M.M

Source/Further Reading: http://mivo-sys.tripod.com/limnic.html
Photo credit and source/further reading: http://suite101.com/article/1986-limnic-eruption-of-lake-nyos-a111515

110 notes

distant-traveller:

Shadows and plumes across Enceladus

Why does Enceladus have ice plumes? The discovery of jets spewing water vapor and ice was detected by the Saturn-orbiting Cassini spacecraft in 2005. The origin of the water feeding the jets, however, remained a topic of research. A leading hypothesis held that the source might originate from a deep underground sea, but another hypothesis indicated that it might just be ice melted off walls of deep rifts by the moon’s tidal flexing and heating. Pictured above, the textured surface of Enceladus is visible in the foreground, while rows of plumes rise from ice fractures in the distance. These jets are made more visible by the Sun angle and the encroaching shadow of night. Recent study of over a hundred images like this — of geysers crossing Enceladus’ South Pole, together with regional heat maps, indicate that these plumes likely originate from a hidden sea, increasing the chance that this frosty globe might be harboring life.

Image credit: Cassini Imaging Team, SSI, JPL, ESA, NASA

distant-traveller:

Shadows and plumes across Enceladus

Why does Enceladus have ice plumes? The discovery of jets spewing water vapor and ice was detected by the Saturn-orbiting Cassini spacecraft in 2005. The origin of the water feeding the jets, however, remained a topic of research. A leading hypothesis held that the source might originate from a deep underground sea, but another hypothesis indicated that it might just be ice melted off walls of deep rifts by the moon’s tidal flexing and heating. Pictured above, the textured surface of Enceladus is visible in the foreground, while rows of plumes rise from ice fractures in the distance. These jets are made more visible by the Sun angle and the encroaching shadow of night. Recent study of over a hundred images like this — of geysers crossing Enceladus’ South Pole, together with regional heat maps, indicate that these plumes likely originate from a hidden sea, increasing the chance that this frosty globe might be harboring life.

Image credit: Cassini Imaging Team, SSI, JPL, ESA, NASA

(Source: apod.nasa.gov, via circuitdesign)

11,508 notes

the-science-llama:

Perseid Meteor ShowerNot as great as last year but still worthy of watching. The Full Moon will compete with the shower this year, lowering the peak-rates to around 40 or 60 meteors per hour at best, even in the darkest of skies. The peak time is Aug 10-13 but you can see meteors for about a week before and after, so start watching now! The earlier you watch, the less the moon will be in the way, so watching a few days before the peak might actually be better if not the same. For more stargazing events this month, see What’s Up for August. Also, Semi-Relevant/Informative post from last year

the-science-llama:

Perseid Meteor Shower
Not as great as last year but still worthy of watching. The Full Moon will compete with the shower this year, lowering the peak-rates to around 40 or 60 meteors per hour at best, even in the darkest of skies. The peak time is Aug 10-13 but you can see meteors for about a week before and after, so start watching now! The earlier you watch, the less the moon will be in the way, so watching a few days before the peak might actually be better if not the same. For more stargazing events this month, see What’s Up for August. Also, Semi-Relevant/Informative post from last year

(via fuckyeah-stars)

96 notes

distant-traveller:

Rosetta’s rendezvous

On August 3rd, the Rosetta spacecraft’s narrow angle camera captured this stunning image of the nucleus of Comet 67P/Churyumov-Gerasimenko. After 10 years and 6.5 billion kilometers of travel along gravity assist trajectories looping through interplanetary space, Rosetta had approached to within 285 kilometers of its target. The curious double-lobed shape of the nucleus is revealed in amazing detail at an image resolution of 5.3 meters per pixel. About 4 kilometers across, the comet nucleus is presently just over 400 million kilometers from Earth, between the orbits of Jupiter and Mars. Now the first spacecraft to achieve a delicate orbit around a comet, Rosetta will swing to within 50 kilometers and closer in the coming weeks, identifiying candidate sites for landing its probe Philae later this year.

Image credit: ESA / Rosetta / MPS for OSIRIS Team; MPS/UPD/LAM/IAA/SSO/INTA/UPM/DASP/IDA

distant-traveller:

Rosetta’s rendezvous

On August 3rd, the Rosetta spacecraft’s narrow angle camera captured this stunning image of the nucleus of Comet 67P/Churyumov-Gerasimenko. After 10 years and 6.5 billion kilometers of travel along gravity assist trajectories looping through interplanetary space, Rosetta had approached to within 285 kilometers of its target. The curious double-lobed shape of the nucleus is revealed in amazing detail at an image resolution of 5.3 meters per pixel. About 4 kilometers across, the comet nucleus is presently just over 400 million kilometers from Earth, between the orbits of Jupiter and Mars. Now the first spacecraft to achieve a delicate orbit around a comet, Rosetta will swing to within 50 kilometers and closer in the coming weeks, identifiying candidate sites for landing its probe Philae later this year.

Image credit: ESA / Rosetta / MPS for OSIRIS Team; MPS/UPD/LAM/IAA/SSO/INTA/UPM/DASP/IDA

(Source: apod.nasa.gov, via circuitdesign)

12 notes

entertainmentnerdly:

Pingualuit impact crater in northern Quebec. Rising 140m from the surrounding tundra, it is 3.44km in diameter and ~1.4 million years old. It is one of the deepest lakes in North America (400m), and contains some of the purest fresh water in the world. [6000x4000] via /r/EarthPorn http://ift.tt/1uDGwTD

entertainmentnerdly:

Pingualuit impact crater in northern Quebec. Rising 140m from the surrounding tundra, it is 3.44km in diameter and ~1.4 million years old. It is one of the deepest lakes in North America (400m), and contains some of the purest fresh water in the world. [6000x4000] via /r/EarthPorn http://ift.tt/1uDGwTD