Tag Archives: clay

Curiosity Rover finds clay cache on Mars — potential sign of water

Curiosity’s drilling instrument has gathered two samples from a Martian soil unit geologists called the “clay-bearing” unit. Worthy of its name, the unit turned out to contain a substantial amount of clay — a mineral typically formed in the presence of water.

The rover snapped this selfie after gathering the samples. To the lower-left of the rover are its two recent drill holes, at targets called “Aberlady” and “Kilmarie.” Image credits: NASA/JPL-Caltech/MSSS.

Although the Curiosity Rover was expected to run for two years, it’s still providing valuable information now, seven years after its landing in 2012. The rover is currently located on the side of lower Mount Sharp, in an area that drew the attention of NASA scientists even before Curiosity landed on Mars because it seemed to contain quite a lot of clay. Prosaically, they called it the “clay-bearing unit“.

However, prosaic or not, the name was very accurate. Curiosity harvested two small drills in the area, using its CheMin instrument (Chemistry and Mineralogy) to confirm that the unit has the highest amounts of clay minerals ever found on Mars.

This animation shows the initial proposed route for NASA’s Curiosity rover on Mount Sharp on Mars. The annotated version of the map labels different regions that scientists working with the rover would like to explore in the coming years. Image credits: NASA/JPL-Caltech/ESA/University of Arizona/JHUAPL/MSSS/USGS Astrogeology Science Center.

This strongly suggests that this area on Mount Sharp contained significant amounts of water. Clays typically form over long periods of time, through a process of weathering and accumulation of diluted solvents. Judging by the appearance and chemistry of this clay (which also includes very small amounts of hematite, an iron oxide that was abundant in the vicinity of the clay-bearing unit), it seems that these rocks formed as layers of mud in ancient lakes.

It’s not the first time Curiosity has found traces of ancient water on Mars. Time and time again, the rover has confirmed that water once flowed on Mars, sparking a heated debate about the possibility of microbial life on the Red Planet. Unfortunately, Curiosity is not well-equipped to look for signs of life so for now, that will remain a matter of speculation.

NASA’s Curiosity Mars rover imaged these drifting clouds on May 17, 2019, Image credits: NASA/JPL-Caltech.

After the analysis, the rover took a well-deserved rest, taking advantage of the moment using its black-and-white Navigation Cameras (Navcams) to snap images of drifting Martian clouds. NASA believes these are likely water-ice clouds — so Curiosity is not only finding water beneath the ground — it’s also finding it in the sky.

Massive sinkhole opens up in Ottawa, thankfully without victims

A massive sinkhole formed in Ottawa, Canada on Wednesday 8th of June, leading to the collapse of one of the city’s busiest streets and damaging gas and water lines in the area. Gas, electrical and water services in downtown Ottawa are temporarily cut off and roadblocks set in areas of the city while authorities scramble to stabilize the area.

The sinkhole damaged the street and buildings in the area.
Image via reddit

First signs of the sinkhole forming were reported at around 10:30 local time on Wednesday near the Canadian Parliament building in downtown Ottawa, Canada. The area, which grew to a large section of the Rideau Street, eventually collapsed later in the day. The street has been closed off to most traffic for some time now — except for a few taxis, buses and pedestrians — due to ongoing construction works. Several nearby buildings had to be evacuated but there thankfully were no immediate reports of injury or deaths caused by the collapse.

Some suggest that the ongoing work on the underground railway system below Rideau Street may have lead to the collapse, but it is still unclear whether the ongoing project had something to do with the appearance of the sinkhole, said Ottawa Mayor Jim Watson. The city is largely built on a type of soil known as Leda clay or quick clay, known for its tendency to collapse. It’s not the first time such a collapse happened in the city; in 2014, a smaller sinkhole formed in an area east of the city, believed to have been caused by a failure in a water line. In 2010 a massive sinkhole suddenly collapsed in north-east Montreal, destroying an entire house and killing four people.

But no matter how it formed, authorities are now looking for solutions, trying to figure out the best way of patching up the massive sinkhole that is now causing a major disruption in one of Ottawa’s primary streets. City officials were forced to temporarily cut off some water, gas and electrical services in downtown Ottawa and roadblocks had been set up as well in different parts of the city for public safety.

“All hands are on deck to make sure the site is secured and no harm is done to any individual,” Watson told reporters on Wednesday.

Watson said they are planning to use a special type of concrete to help stabilize the sinkhole. This might take some time, however, and people should be prepared for some delays.

Video credits CBC News

 

Canadian clay kills antibiotic-resistant bacteria on contact

Canadian aboriginals have been using clay to treat their ailments for centuries. Now, a new study has found not only that the clay does have antibacterial properties, but that the clay can actually wipe out antibiotic-resistant bacteria.

Image via University of Columbia.

As we use more and more antibiotics, more and more bacteria are starting to resist this type of treatment. The WHO has warned against an impeding crisis in global healthcare, a crisis which we are not equipped to deal with. Now, we may be getting an unlikely ally in the form of clay.

The so-called ESKAPE pathogens — Enterococcus faecium, Staphylococcus aureus (MRSA), Klebsiella pneumoniae, Acinetobacter baumannii, Pseudomonas aeruginosa, and Enterobacter species — cause the majority of U.S. hospital infections and effectively ‘escape’ the effects of antibacterial drugs. A survey conducted at 97 hospitals showed the rate of MRSA in diabetic foot infections to have almost doubled between 2003 and 2007, and the trend is accelerating even more in recent years.

“Infections caused by ESKAPE bacteria are essentially untreatable and contribute to increasing mortality in hospitals,” said UBC microbiologist Julian Davies, co-author of the paper published today in the American Society for Microbiology’s mBio journal.

This is what makes this discovery even more exciting and surprising: the fact that clay can make a difference in such a difficult environment. In the in vitro testing conducted by Davies and UBC researcher Shekooh Behroozian, clay suspended in water killed 16 strains of ESKAPE bacteria samples from sources including Vancouver General Hospital, St. Paul’s Hospital, and the University of British Columbia’s wastewater treatment pilot plant. Also, no side effects were reported.

“After 50 years of over-using and misusing antibiotics, ancient medicinals and other natural mineral-based agents may provide new weapons in the battle against multidrug-resistant pathogens.”

The clay deposit researchers used is located on Heiltsuk First Nation’s traditional territory, 400 kilometres north of Vancouver, Canada, in a shallow five-acre granite basin.

It’s thrilling to see how interdisciplinary mixed teams work so well together. Now, mineralogical and chemical analysis are also being conducted to better understand how the clay works and where other deposits might also be found.

Journal Reference: Kisameet Clay Exhibits Potent Antibacterial Activity against the ESKAPE Pathogens
mBio American Society for Microbiology

January/February 2016 Volume 7 Issue 1 e01842-15

UBC researchers Julian Davies and Shekooh Behroozian with their 'magic' clay.

Clay used by the First Nations people destroys fatal drug-resistant pathogens

A team at University of British Columbia claims that a type of clay found northwest of Vancouver is effective against a dangerous class of drug-resistant bacteria. These germs are called ESKAPE bacteria because they don’t seem to respond to any anti-microbial medication, escaping any agent we throw at them and causing extensive morbidity and mortality in infected patients. Once patients get infected with ESKAPE bacteria, there is no available treatment and most die, ironically in a hospital where the drug-resistant germs congregate. The clay investigated by the Canadian researchers destroyed the ESKAPE germs, in some instances in less than 5 hours. Furthermore, the clay is completely natural and no toxic side-effects have been reported thus far.

 UBC researchers Julian Davies and Shekooh Behroozian with their 'magic' clay.

UBC researchers Julian Davies and Shekooh Behroozian with their ‘magic’ clay.

“More than 50 years of misuse and overuse of antibiotics has led to a plague of antibiotic resistance that threatens to reduce the efficacy of antimicrobial agents available for the treatment of infections due to resistant organisms,” reads the paper.

“The main threat is nosocomial infections in which certain pathogens, notably the ESKAPE organisms, are essentially untreatable and contribute to increasing mortality and morbidity in surgical wards.”

The  Kisameet clay (KC), a natural clay mineral from British Columbia, has been widely known for its therapeutic qualities for many years. Anecdotal evidence suggests that it was used by the local First Nations (Heiltsuk) people for several centuries for a variety of ailments, including ulcerative colitis, duodenal ulcer, arthritis, neuritis, phlebitis, skin irritation, and burns. Such is the case with other clay minerals, not just KC, however no such therapy has  been approved by regulatory agencies in Canada.

What KC looks like. It's been used for medicinal purposes for thousands of years.

What KC looks like. It’s been used for medicinal purposes for hundreds of years.

The researchers at University of British Columbia are among the first to perform an extensive study of the therapeutic effects of KC.They collected 16 ESKAPE pathogen strains from a number of sources in Vancouver, including Vancouver General Hospital (VGH), St. Paul’s Hospital (SPH), and the University of British Columbia (UBC) wastewater treatment pilot plant (WWTP). Each strain was grown in-vivo in Luria-Bertani (LB) broth or on LB agar.

When all else fails, this clay shines

Tests were performed using a panel of 36 antibiotics. These showed that the pathogens were resistant to the antibiotics, though with variability in their resistance. The presence of KC dramatically reduced the viability of all strains tested, though.

“For example, after a 5-h exposure to KC, no viable cells of A. baumannii AB-1270, Enterobacter sp. strain MI1, or Enterobacter sp. strain MI16 could be recovered, indicating potent activity against these strains. S. aureus, K. pneumoniae, P. aeruginosa, A. baumannii AB-1264, and Enterobacter cloacae 1172 lost viability completely after 24 h, and the same killing took 48 h for E. faecium strains. In contrast, in water-only controls without KC, the decline in CFU during the same period of incubation was ≤1 log10 for all Gram-negative strains and ~1 to 3 log10 for E. faecium and S. aureus strains, respectively.”

The researchers were extremely surprised to find out the clay had killed at 16 strains! “They wanted microbial testing on clay, so I was a bit skeptical at first,” said UBC microbiologist Julian Davies. “Well, there are all sorts of claims out there, all kinds of folklore medicine and witchcraft.”

We’re beginning to run out of weapons against bacteria, which have caught on to our tricks. It may be only a matter of time until our anti-microbial arsenal is exhausted. Fatalities from ESKAPE pathogens will only increase in time, but there is progress. For one, there’s KC which definitely warrants more attention from the medical community (it works against fungal infections as well). Previously last week, I wrote about how nanoparticles activated by light selectively kill drug-resistant bacteria. The future isn’t as gloom as it seems, but such efforts require support, as Dr. Mark Blaskovich urged in a ZME Science guest post.

The clay is a complex mixture made up of about 24% by weight clay minerals, which are aluminum silicates, with various exchangeable metal ions and elemental sulfur. So, we don’t know for sure what makes KC so good at killing germs — even the toughest ones. “So far, we are sure that the mechanism of action is multifactorial,” says graduate student Shekooh Behroozian. “And we know the antimicrobial activity is pH-dependent, with the clay showing the best activity at acidic pH.”

“It’s a dream that there could be isolates [in the clay] that make new antibiotics,” says Davies. But the clay must be tested for toxicity and its activity defined well enough to satisfy drug regulators, he added.

Colorado Mudslide seen from outer space

A month ago, on May 25, a large mudslide rushed down a Colorado mountain near the town of Collbran covering an area three miles long and one-half to three-quarters of a mile wide. It claimed the lives of three ranchers, caused a small earthquake and covered an area three miles long and one-half to three-quarters of a mile wide.

You can see the huge extent of the mudslide in the pictures above, which was taken by the Landsat 8 satellite on June 7. The lower image, taken by Landsat 8 on June 20, 2013, shows the slide region before the slide; on average, Colorado experiences thousands of landslides each year, but very few reach this magnitude. This region in particular, the Grand Mesa region of western Colorado, is extremely prone to landslides due to the underlying geology.

What we have there is a heavy layer of basalt ontop of soft claystone that erodes easily. When the water starts to erode the claystone, the basalt above starts to slip, catching more and more mass in its movement; the phenomenon is more prone in the spring, when there is a large quantity of water around from meltoff and increased rainfall.

Image via Baum and Odum, 1996.

The slide contains a pool of water at the top, and a large block of earth towards where the slide originated. Geologists now estimate that pool will hold about 245 acre feet of water before it could reach an outlet and spill over

 

Huge freshwater reserves found beneath oceans

Scientists have found huge reserves of freshwater in a totally unexpected area: several kilometers offshore, beneath the oceans. This new discovery has the potential to avert or at least minimize the effects of the almost certain water crisis some areas of the world will be facing in future years.

New research suggests that half a million cubic kilometers of low-salinity water are buried beneath the seabed on continental shelves around the world. (Credit: © DJ / Fotolia)

A new study published in Nature reveals that an estimated half a million cubic kilometers of low-salinity water are buried beneath the seabed on continental shelves all around the world. The water has been located off Australia, China, North America and South Africa, but it’s very likely that the same can be found in many more areas throughout the world.

“The volume of this water resource is a hundred times greater than the amount we’ve extracted from the Earth’s sub-surface in the past century since 1900,” says lead author Dr Vincent Post (pictured) of the National Centre for Groundwater Research and Training (NCGRT) and the School of the Environment at Flinders University.
“Knowing about these reserves is great news because this volume of water could sustain some regions for decades.”

Geologists have known for some time that freshwater can be found under the seafloor, but they thought that it only occurred under rare and special conditions.

“Our research shows that fresh and brackish aquifers below the seabed are actually quite a common phenomenon,” he says.

These reserves were formed several thousands of years ago (or perhaps even more), when the sea levels were much lower than today and the coastline was further out. Dr. Post explains:

“So when it rained, the water would infiltrate into the ground and fill up the water table in areas that are nowadays under the sea. “It happened all around the world, and when the sea level rose when ice caps started melting some 20,000 years ago, these areas were covered by the ocean. “Many aquifers were — and are still — protected from seawater by layers of clay and sediment that sit on top of them.”

An aquifer is an underground layer of water-bearing permeable rock or unconsolidated materials (gravel, sand, or silt) from which groundwater can be extracted using a water well. Basically, underground aquifers contain water and are isolated from what’s surrounding them by impermeable layers – usually clay.

While offshore drilling can be very costly, many areas of the world are overconsuming water, and, inevitably, the water reserves will start running low. As the resource is becoming scarcer and scarcer, at one point, it may likely become feasible to extract this type of water.

“Freshwater on our planet is increasingly under stress and strain so the discovery of significant new stores off the coast is very exciting. It means that more options can be considered to help reduce the impact of droughts and continental water shortages.

Journal Reference:

  1. Vincent E.A. Post, Jacobus Groen, Henk Kooi, Mark Person, Shemin Ge, W. Mike Edmunds. Offshore fresh groundwater reserves as a global phenomenonNature, 2013; 504 (7478): 71 DOI: 10.1038/nature12858