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Classification of Rocks Simple digram.

The Rock Cycle_ Learn The Types Of Rocks & Minerals

A Year of Surprising Science From NASA's InSight Mars Mission A batch of new papers summarizes the lander's findings above and below the surface of the Red Planet.

Building a Long-Term Record of Fire

The control of fire is a goal that may well be as old as humanity, but the systematic monitoring of fire on a global scale is a much newer capability.

In the 1910s, the U.S. Forest Service began building fire lookout towers on mountain peaks in order to detect distant fires. A few decades later, fire-spotting airplanes flew onto the scene. Then in the early 1980s, satellites began to map fires over large areas from the vantage point of space.

Over time, researchers have built a rich and textured record of Earth’s fire activity and are now able to analyze decadal trends. “The pace of discovery has increased dramatically during the satellite era,” said James Randerson, a scientist at the University of California, Irvine. “Having high-quality, daily observations of fires available on a global scale has been critical.”

The animation above shows the locations of actively burning fires on a monthly basis for nearly two decades. The maps are based on observations from the Moderate Resolution Imaging Spectroradiometer (MODIS) on NASA’s Terra satellite. The colors are based on a count of the number (not size) of fires observed within a 1,000-square-kilometer area. White pixels show the high end of the count—as many as 30 fires in a 1,000-square-kilometer area per day. Orange pixels show as many as 10 fires, while red areas show as few as 1 fire per day.

The sequence highlights the rhythms—both natural and human-caused—in global fire activity. Bands of fire sweep across Eurasia, North America, and Southeast Asia as farmers clear and maintain fields in April and May. Summer brings new activity in boreal and temperate forests in North America and Eurasia due to lighting-triggered fires burning in remote areas. In the tropical forests of South America and equatorial Asia, fires flare up in August, September, and October as people make use of the dry season to clear rainforest and savanna, as well as stop trees and shrubs from encroaching on already cleared land. Few months pass in Australia without large numbers of fires burning somewhere on the continent’s vast grasslands, savannas, and tropical forests.

But it is Africa that is truly the fire continent. On an average day in August, the Moderate Resolution Imaging Spectroradiometers (MODIS) on NASA’s Aqua and Terra satellites detect 10,000 actively burning fires around the world—and 70 percent them happen in Africa. Huge numbers of blazes spring up in the northern part of continent in December and January. A half year later, the burning has shifted south. Indeed, global fire emissions typically peak in August and September, coinciding with the main fire seasons of the Southern Hemisphere, particularly Africa. (High activity in temperate and boreal forests in the Northern Hemisphere in the summer also contribute.)

Though Africa dominates in the sheer number of fires, fires seasons there are pretty consistent from year-to-year. The most variable fire seasons happen elsewhere, such as the tropical forests of South America and equatorial Asia. In these areas, the severity of fire season is often linked to cycles of El Niño and La Niña. The buildup of warm water in the eastern Pacific during an El Niño changes atmospheric patterns and reduces rainfall over many rainforests, allowing them to burn more easily and widely.

espite the vast quantities of carbon released by fires in savannas, grasslands, and boreal forests, research shows that fires in these biomes do not generally add carbon to the atmosphere in the long term. The regrowth of vegetation or the creation of charcoal typically recaptures all of the carbon within months or years. However, when fires permanently remove trees or burn through peat (a carbon-rich fuel that can take centuries to form), little carbon is recaptured and the atmosphere sees a net increase in CO2.

That is why outbreaks of fire in countries with large amounts of peat, such as Indonesia, have an outsized effect on global climate. Fires in equatorial Asia account for just 0.6 percent of global burned area, yet the region accounts for 8 percent of carbon emissions and 23 percent of methane emissions.

One of the most interesting things researchers have discovered since MODIS began collecting measurements, noted Randerson, is a decrease in the total number of square kilometers burned each year. Between 2003 and 2019, that number has dropped by roughly 25 percent.

As populations have increased in fire-prone regions of Africa, South America, and Central Asia, grasslands and savannas have become more developed and converted into farmland. As a result, long-standing habits of burning grasslands (to clear shrubs and land for cattle or other reasons) have decreased, explained NASA Goddard Space Flight scientist Niels Andela. And instead of using fire, people increasingly use machines to clear crops.

“There are really two separate trends,” said Randerson. “Even as the global burned area number has declined because of what is happening in savannas, we are seeing a significant increase in the intensity and reach of fires in the western United States because of climate change.”

When researchers began using satellites to study the world’s fires in the 1980s, they were just sorting out the basics of how to detect fires from space. Now after mining MODIS data for nearly two decades, scientists are looking ahead to other satellites and technologies that they hope will advance the study of fire in the coming years.

A series of follow-on sensors called the Visible Infrared Imaging Radiometer Suite (VIIRS) on the Suomi NPP and NOAA-20 satellites now make near-real time observations of emissions that are even more accurate than those from MODIS because of improved fire detections along the edge of the edges of images, noted Andela.

Meanwhile, the launch of satellites with higher-resolution sensors is also helping. “The Landsat 8 and Sentinel satellites, in particular, are contributing to a revolution in our ability to measure the burned area of small grassland and forest fires,” said Randerson. “And we are going to need additional detection capabilities in the coming years to track increasingly destructive mega fires during all times of day and night.”

Read the full story and see more imagery here:
https://earthobservatory.nasa.gov/images/145421/building-a-long-term-record-of-fire

Building a Long-Term Record of Fire Scientists have answered some important questions about how fires vary around the world and are changing over time.

New Mars rover named after DNA pioneer Rosalind Franklin - Daily Times A British-made rover that will set off for Mars next year in search for signs of life was named Thursday after DNA pioneer Rosalind Franklin. UK astronaut Tim Peake revealed the name of the first European scavenger of the Red Planet at the Airbus factory just north of London where it was built. Camb...

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Earth's Missing Crust Was Removed by Glaciers,


The area marked in orange shows unconformity between horizontal Tonto Group rocks of the Cambrian Period on top of tilted Grand Canyon Supergroup rocks. WIKIPEDIA
If you're a geochronologist — someone who studies the age of our planet and its rock formations — you spend a lot of time around zircons. They're durable crystals found in a variety of rocks, and because they preserve crucial data about the deep past, zircons are lovingly called "time capsules." Recently, researchers used zircons to take a crack at one of prehistory's greatest riddles.

About 540 million years ago, the Cambrian Period began. An important time for life on Earth, it left a diverse fossil record behind and marked the dawn of our current eon. In many places around the world, such as the Grand Canyon, we find Cambrian rock deposits sitting right on top of rocky layers that are between 250 million and 1.2 billion years old. Needless to say, that's quite an age gap. Called the Great Unconformity, the divide between those two layers is a puzzle to scientists. What's the story there? Did millions of years' worth of rock suddenly go missing?


A study in December 2018 set to find out and claims the crust was sheared away by glaciers at a time when most — or all — of the world's surface was coated with ice. That epic bulldozing session may have also created the right conditions for complex organisms, like our own ancestors, to flourish. The paper, "Neoproterozoic Glacial Origin of the Great Unconformity," was published in the journal Proceedings of the National Academy of Sciences.

Crystal Gazing
University of California, Berkeley geologist C. Brenhin Keller led the study. In an email, he writes that his team drew upon existing literature to compile a huge body of relevant info on geochemistry and rock layers. Keller says the data they amassed represented "many thousand hours of both fieldwork and analytical time, conducted by hundreds of people over many years."

Zircons were the main focus. Usually, zircon crystals are created when silica-rich magma cools down. "Like any natural system, magmas are rich brews, full of other elements," study co-author John Husson explains via email. "And some of those elements are able to substitute [themselves] into zircon's structure."

For instance, zircons often contain uranium, which slowly decays and converts into lead. So when scientists look at the composition of uranium/lead samples inside a zircon, they can figure out how old the crystal is. It's radiometric dating at its finest.

Curious Elements
Keller and company reviewed the data on 4.4 billion years' worth of preserved zircon crystals. Those from early Cambrian rocks had a couple of surprises in store.

Earth's crust sits on top of a layer called the mantle. A thick buffer zone that's primarily made of solid rock, the mantle separates us from the inner core of our planet. Certain elements feel more at home down in the mantle than they do on the crust. Lutetium is a good example. Just as uranium decays into lead, lutetium gradually transforms into a certain hafnium isotope over time.

Keller says when Earth's solid mantle "partially [melts] ... more lutetium tends to stay in the mantle." In the process, "more hafnium goes into new magma" that's liable to get pushed through a volcano, spill out onto the surface, and become hardened rock.

Elizabeth Bell — another scientist who worked on the study — explained via email, hafnium isotopes can therefore help us figure out just how old "the materials that melted into a magma" were. That's a helpful quality. By looking at hafnium isotope ratios in Cambrian zircons, Bell and her colleagues realized that the crystals came from magma that was once very old, very solid crust.

Somehow, this raw material was driven down into the mantle, where it melted. Then it returned to the surface, cooled and became solid crust again. Along the way, the well-traveled rock came into contact with really cold liquid water — as evidenced by a tell-tale oxygen isotope found in the same zircons.

Ice, Rock and Magma
Since glaciers are agents of erosion, Keller's team proposes that the Great Unconformity was created when glacial activity drove a huge amount of our planet's crust into the ocean during the snowball Earth years.

The so-called "snowball Earth" hypothesis claims that between 750 and 610 million years ago, glaciers periodically coated our planet, extending all the way from the poles to the equator. Wild as it may sound, the basic premise is popular among geologists (though some researchers don't think the oceans froze over — at least, not entirely).

Keller, Husson and Bell envision the walls of ice behaving like giant scythes. All the world's major landmasses would have been trimmed down; the typical continental crust might have lost 7.4 miles (12 kilometers) of vertical rock to the shearing glaciers. After being pushed onto the ocean floor, the displaced crustal rock was eventually subducted into Earth's mantle and later recycled. Or so goes the new hypothesis.

(At this point, we should mention that the recently published study contradicts a February 2018 paper published in the journal Earth and Space Science that speculates the snowball Earth period may have happened after a time of mass erosion created the Great Unconformity.)

Life Goes On
If Keller's team is correct in its hypothesis, we might have an explanation for why there aren't many meteorite impact craters that predate the snowball Earth phase. Theoretically, the grating glaciers would've stripped most of the older ones away. En route, the ice may have also opened the door for complex life-forms — which didn't start to appear until about 635 to 431 million years ago — to evolve.

"While the snowball [Earth] itself would have been a pretty harsh environment for life, one implication of [our] study is that the erosion of this much crust could have freed up a lot of phosphorous trapped in igneous rocks," Keller explains. Phosphorous, he notes, is "a critical part of DNA and ATP" and something all contemporary organisms require.

NOW THAT'S INTERESTING
Sir Douglas Mawson was one of the founding fathers of the snowball Earth hypothesis. An adventurer as well as a geologist, he was the sole survivor of a three-man trek across Antarctica that began in the year 1912. At one point, Mawson had to walk alone over 100 miles (161 kilometers) of frigid terrain in order to meet up with his eventual rescuers.
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Camp Fire Rages in California

On November 8, 2018, the Camp Fire erupted 90 miles (140 kilometers) north of Sacramento, California around 6:29am Pacific Standard Time. By 8:00pm, the fire had charred around 20,000 acres and remained zero percent contained.

The Operational Land Imager on Landsat 8 acquired this image on November 8, 2018, around 10:45 a.m. Pacific Standard Time (06:45 Universal Time). The natural-color image was created using bands 4-3-2, along with shortwave infrared light to highlight the active fire.

Read more: https://earthobservatory.nasa.gov/images/144225/camp-fire-rages-in-california

Camp Fire Rages in California The fast-moving Camp Fire threatens several towns.

There's a new force on the scene for NASA scientists studying carbon from space -- the Global Ecosystem Dynamics Investigation, GEDI. The instrument will launch to the International Space Station, where it will travel over Earth's light and dark sides and measure carbon stored in forests.

GEDI works by bouncing 8 laser beams off Earth's surface, and timing how long it takes them to strike back to the spacecraft. Over time, GEDI will help scientists build a 3D map of forest canopy and structure around the planet, to calculate how much carbon is stored in vegetation. Carbon is a greenhouse gas, so understanding how forests store carbon is important to forecasting and mitigating climate change.

NASA Goddard built the instrument in collaboration with the University of Maryland. From Endor to Earth, GEDI will improve our understanding of how carbon is stored in trees.

https://go.nasa.gov/2OwD6xm

A New Hope: GEDI to Yield 3D Forest Carbon Map A new NASA laser instrument set to launch to the International Space Station in December will help scientists create the first three-dimensional map of the world’s temperate and tropical forests.

English: MAVEN at Mars, Artist's Concept. This artist's concept depicts NASA's Mars Atmosphere and Volatile EvolutioN (MAVEN) spacecraft near Mars. MAVEN launched late in 2013 and entered orbit around Mars September 2014. It has been described as the first mission devoted to understanding the Martian upper atmosphere. The mission's principal investigator is Bruce Jakosky from the Laboratory for Atmospheric and Space Physics at the University of Colorado.

The goal of MAVEN is to determine the role that loss of atmospheric gas to space played in changing the Martian climate through time. MAVEN will determine how much of the Martian atmosphere has been lost over time by measuring the current rate of escape to space and gathering enough information about the relevant processes to allow extrapolation backward in time. In 2018 its mission responsibilities were extended, and its orbit modified, to include communication with surface experiments such as the Curiosity rover.

NASA Goddard Space Flight Center in Greenbelt, Md. manages the project and built some of the instruments for the mission. In addition to the principal investigator coming from CU-LASP, the university has provided science operations, built instruments, and led education/public outreach. Lockheed Martin of Littleton, Colo., built the spacecraft and has been performing mission operations. The University of California-Berkeley Space Sciences Laboratory was another instrument builder for the mission. NASA's Jet Propulsion Laboratory, Pasadena, Calif., has provided navigation support, the Deep Space Network, and the Electra telecommunications relay hardware and operations.

For more information about MAVEN, visit www.nasa.gov/maven.