First noticed by westerners in 1965, when the Gemini-4 spacecraft flew over northwest Africa (alternate source, with link to uncompressed TIF | in Earth photographs from Gemini III, IV, and V on Archive.org), the Richat Structure in the Sahara desert of west–central Mauritania resembles an impact crater or a circular target (or a possible Atlantis, or Plato's circular city, or maybe an open-pit mine), but is a naturally occurring 40-50 km (25-30 mi) geologic dome that has eroded over time. It's large enough that, when seen in person, the scale of the geography is hard to capture. But it is quite impressive when seen from space (mentioned previously)
The Timeline of the Far Future is a Wikipedia article which serves as a gateway to a ton of fascinating scientific topics on the far edge of human understanding: ~50,000 years from now the Earth will enter a new Glacial period; ~100,000 years from now the Earth will likely have experienced a supervolcanic eruption; ~10,000,000 years from now the East African Rift divides the continent of Africa in to two land masses; ~20,000,000,000 years from now the Universe effectively dies due to The Big Rip.
Ron Blakey makes paleogeographic maps of the ancient world.
The paleogeographic maps show the varied landscapes of the ancient Earth through hundreds of millions of years of geologic time, including distribution of ancient shallow seas, deep ocean basins, mountain ranges, coastal plains, and continental interiors. Tectonic features shown include subduction zones, island arcs, mid-ocean ridges and accreting terranes.
That rover the United States sent to Mars found something. It won't blow your mind, but it's interesting if you're into Mars geology.
To a fisherman, all areas of the sea have names, just as a farmer will name his fields or streets have formal and informal names. For instance, there is the Witch's Ground, an area where the fishing is good, but the bottom is very rough and gear can easily be damaged or lost. Or if you're really unlucky, an undersea methane burst might make water less dense, and the sea could swallow your whole trawler. [more inside]
Let's take another look at Chris Wayan's PLANETOCOPIA (previously): A series of detailed conceptions and paintings of vastly different Earths based on differing climates and land mass position. A planet designed to speed up East-West cvilization development! A life-bearing super hot world! An Earth with most of the seas missing! Forever Ice Age Earth! [more inside]
Researchers in the Earth Sciences and Art departments at Syracuse University melt basalt and make their own lava flows for science and art! Here's the project's homepage, including videos. via make blog
A history of the world. As seen from space. Over a really long stretch of time. If the Earth is about 4.5 billion years old, and Pangea split up only about 200 million years ago, what happened before then? I never knew that geologists could reconstruct the continents' movements from before Pangea. Not only that, but they can give us a preview of what comes next. Here's three possible ways the continents might be joined in 250 million years. In the big picture, researchers from U.C. Lancashire have just finished a model of the way the Milky Way Galaxy formed. [more inside]
Understand something of the earth beneath your feet and the landscape in front of you. These sites provide a chance to see geologic sites and also see expert interpretations. Geology of Southern England's Jurassic Coast - many pages with detailed strata and sometimes questions to challenge yourself (click photos to enlarge), by Ian West of Southampton University. [more inside]
British scientists have discovered a “treasure trove” of Charles Darwin fossils that have been lost for more than 150-years. | 'I spotted some drawers marked "unregistered fossil plants",' he recalls. 'I can't resist a mystery, so I pulled one open. What I found inside made my jaw drop!' Inside were hundreds of fossil plants, polished into thin translucent sheets known as 'thin sections' and captured in glass slides so they could be studied under a microscope. | The British Geologic Survey has images 33 of the "Lost Fossils" online. [more inside]
39 years ago today, Apollo 17 splashed down in the South Pacific, marking the end to manned exploration of the Moon. What we learned from those 10 years of discovery was amazing. [more inside]
Libyan Desert Glass is strewn over an area of hundreds of square kilometers in the Great Sand Sea, a region desolate even by the high standards of the Sahara. As one account of a recent trip to acquire Libyan Desert Glass puts it: "Out there, death sits on your shoulder like a vulture." While some would have you believe that Libyan Desert Glass is evidence of ancient atomic warfare, it is probably evidence of a massive meteorite or comet explosion nearly thirty million years ago, similar to Tunguska, but much bigger. The stone age Aterian peoples made tools from it, but the remoteness and inhospitality of the Great Sand Sea has ensured that until recent times it has mostly been undisturbed. However, a breast ornament buried in Tutankhamen's tomb has a scarab made from Libyan Desert Glass, the only piece made of the material to have been found by Egyptologists, and how Tutankhamen's jewelers acquired it has remained a mystery. Until now. [Previously]
In 1602, a cobbler strolling outside of Bologna discovered a colorless stone with the curious ability to "accumulate light when exposed to the sun and to emit it in the darkness." His lapis solaris was to be the chemical sensation of the century. [more inside]
D-Day's Legacy: Remnants of invasion linger in beach sands - an analysis of the debris left in the sands at Omaha Beach from D-Day. [more inside]
The Mississippi River has the third largest drainage basin in the world, exceeded in size only by the watersheds of the Amazon and Congo Rivers. It drains 41 percent of the 48 contiguous states of the United States. The basin covers more than 1,245,000 square miles, includes all or parts of 31 states and two Canadian provinces. The US Government has tried to improve navigability of the Mississippi River and its major tributaries for more than a hundred years, focused in part by Mississippi River Commission, created in 1879. The river is ever-changing, and in an attempt to understand their domain, and in 1941, MCR hired Harold Norman Fisk to conduct a geological investigation of the Lower Mississippi Valley. The result was a colorful map that displayed the historical course of the riverway from southern Illinois to southern Louisana. His vivid maps are available online in full, but beware: the files are very large.
At the beginning of last month, Scientific American unveiled a new network of 47 blogs with 55 bloggers. Their latest posts can be found here. [more inside]
The sliding rocks of Racetrack Playa in Death Valley, California have mystified and delighted visitors for decades (previously). Now planetary scientist Ralph Lorenz and colleagues think they've figured out how the rocks get around: ice rafts float the rocks out of the mud, reducing friction enough that modest winds can push them along (PDF of Lorenz et al., American Journal of Physics, Vol. 79, 1 January 2011). [more inside]
Die Wunder Gottes in der Natur (1744) illustrates astronomical, meteorological, geological, spiritual, and psychological visions, based on the work of 16th century Alsatian encyclopedist Conrad Lycosthenes.
The cover and title page.
The cover and title page.
New electrical conductivity measurements show the subterranean extent of the Yellowstone supervolcano to be a lot larger than previously known.
Hot Rocks: the winning entries in Wired's geology photography contest.
There are some folks that think a large earthquake could hit the U.S. West Coast in the next few days.
Earth Tides, Syzygy, this weekend's Supermoon, and whale beachings are all things that some folks think point to a possible tectonic event on the U.S. West Coast this weekend. Jim Berkland, retired USGS Geologist thinks so. See his interview here. And, he's got a track record of predicting earthquakes.
Around midnight on January 27, 1700, a mysterious tsunami stole through several villages on the eastern coast of Japan. [more inside]
Since last fall central Arkansas has experienced a mysterious swarm of earthquakes. It's clear that Arkansas has shaken in the past. But the sheer numbers are largely unprecedented and have been dubbed an earthquake swarm by the USGS. The Arkansas Geological Survey says that the quakes have nothing to do with hydraulic fracturing of the Fayetteville Shale. So do energy companies. Not everyone is convinced. [more inside]
SEED Magazine: Wealth of Nations: "Shared natural resources underpin the global economy, but our current economic system does not acknowledge their worth. Can a major new effort to assess the costs of biodiversity loss force a paradigm shift in what we value?" [more inside]
Desert Gazette, "Mojave Desert, True Facts Legends and Lies". With links to other sites about the Mojave, including the excellent Digital Desert. Stories of life and death in the desert. The blogger, Walter Feller's photographs. About the Mojave Desert.
Don't continue fooling yourself. The earth is growing and expanding rapidly. Despite plate tectonics' popular acceptance in the 60s, Samuel Warren Carey, the father of modern expansion tectonics, was publicly promoting his theories of an expanded earth as late as 1981. One of the theory's most prominent modern spokesmen is comics artist Neal Adams, who has created a number of informative videos about a new model of the universe that even manages to explain why the dinosaurs died out. [more inside]
Experts are little help in the constant struggle in this conversation to separate myth from reality, because they have the same difficulty, and routinely demonstrate it by talking past each other. Respected scientists warn of imminent energy shortages as geologic fuel supplies run out. Wall Street executives dismiss their predictions as myths and call for more drilling. Environmentalists describe the destruction to the earth from burning coal, oil, and natural gas. Economists ignore them and describe the danger to the earth of failing to burn coal, oil, and natural gas. Geology researchers report fresh findings about what the earth was like millions of years ago. Creationist researchers report fresh findings that the earth didn’t exist millions of years ago. The only way not to get lost in this awful swamp is to review the basics and decide for yourself what you believe and what you don’t. [more inside]
Oh cool, a thermal video of a Hawaiian volcano. More cool, but non thermal, video of another volcano in Hawaii. Another awesome geographical happening in you know where. Wow, the place is a hotspot for shield volcanoes, even has its own observatory.
For Sale: Rural Italian countryside, Priced to MOVE! A landslide (mud flow?) splits a hillside apart in the southern Italian town of Maierato.
How does an ecosystem rebound from catastrophe? Thirty years after the blast, Mount St. Helens is reborn again. Interactive Graphic: Blast Zone. Also see National Geographic's feature article from 1981, chronicling that year's eruption. Previously on MeFi [more inside]
Pathological geomorphology, the blog. Featuring: dunes vs. river, parabolic [not Barchan] dunes, annular drainage, salt! glaciers, thermokarst, and another structurally controlled lake.
Jared Diamond on the unique cultural and geological challenges Haiti has faced since its colonial days. Diamond shows how these reasons have caused the nation to fare considerably poorer than its neighbor, The Dominican Republic. [more inside]
Last chance to see: Video of Mexico's Naica Cave of Crystals (Previously, and previously.) [more inside]
Petoskey Stones are stones of fossilized coral (Hexagonaria percarinata ) that can be found along the shore of Lake Michigan near the town of Petoskey (Population 6,000). Once polished, they can be beautiful, and are often made into jewelry. It is the state stone of Michigan and is celebrated in an annual festival. The origin of the name of the stone, however, is under contention. [more inside]
The Polar Discovery team has documented science in action from pole to pole during the historic 2007-2009 International Polar Year, and covered five scientific expeditions. The science projects explored a range of topics from climate change and glaciers, to Earth’s geology, biology, ocean chemistry, circulation, and technology at the icy ends of the earth. Through photo essays and other multimedia, they explain how scientists collected data and what they discovered about the rapidly changing polar regions. From the awesome folks at WHOI.
Native American Sites in the City of Philadelphia is a superbly illustrated exposition of the historical development of Philadelphia, with a focus on those few surviving Native American sites which lie under the urban fabric. Lots more excellent Public Archaeology is available from the Philadelphia Archaeological Forum. Bonus link: Philly's lost creeks and streams. [more inside]
Durango Bill's Home Page. With topics that include: 3D end-to-end tour of the Grand Canyon, the origin and formation of the Colorado River, and examples of river systems that cut through mountain ranges instead of taking easier routes around them in Ancestral Rivers of the World. [more inside]
Waterlines is a new online exhibit from the excellent Burke Museum at the University of Washington, Seattle. It tells the story of the land underlying Seattle, one of the United States' most geologically active city sites, and of the human attempts to engineer this landform. Closely related are the archaeology of West Point and Coast Salish Villages of Puget Sound (e.g., read the story of North Wind and Storm Wind).
After months of pre-eruptive activity, Alaska's Mount Redoubt has erupted 6 times since Sunday night. Telegraphing its eruption with massive shallow earthquake activity in the range of 26 earthquakes every 10 minutes, the volcano, located around 100 miles southwest of Anchorage, spewed an ash column 10km high, and is expected to continue erupting for weeks or months. The last time this massive volcano erupted in 1989 a commercial airliner was caught in the ash column, causing the engines to seize and the plane to lose two miles of altitude before the engines were restarted. That eruption, which lasted for 5 months, produced this spectacular photo. Follow this amazing event at the Alaska Volcano Observatory. [more inside]
Cool video of an undersea volcano erupting off Tonga. Spectacular clouds began spewing out of the sea on Monday about 10km from the southwest coast off the main island of Tongatapu, where up to 36 undersea volcanoes are clustered. More on these volcanism blogs.
On June 8, 1783, the volcano Laki in south Iceland tore open a 16-mile fissure that erupted over nine cubic miles of lava. Not only would this eruption kill over 50% of Iceland's livestock population, leading to famine which killed approximately 25% of the population; its effects were felt the world over, with flourine, sulfur dioxide, ash, sand and drastically cooled tempertaures from the blotted-out sun reaching as far afield as North America and Africa. The eruption lasted for nearly eight months. And from the day the eruption began, a humble priest named Jón Steingrímsson would make his mark in history. [more inside]
Where does your water come from? Global water supply chart. Global freshwater resources from the UN.
An erupting stratovolcano poses numerous hazards for nearby habitation, but none nearly so terrifying and deadly as the pyroclastic flow. Pyroclastic flows, comprised of tons of superheated sulfuric gases, particulate rock materials and ash, can reach temperatures of 1,830 °F and travel at alarming speeds up to 450mph. Convection of materials within the clouds causes them to become a suspension, fluidizing and thundering noxiously across the surrounding landscape for miles, in some cases even uphill or across open water. Wherever these clouds come in contact with humans the result is catastrophe, as the residents of Herculaneum and St. Pierre, Martinique learned within minutes of the eruptions of Vesuvius in 79AD and Pelee in 1902-- both towns were overwhelmed by pyroclastic clouds, igniting all flammable materials and incinerating and suffocating the inhabitants. None survived Herculaneum, while just two of St. Pierre's 26,000 survived, one of whom was a prisoner condemned to death and awaiting his execution in a dungeon cell. Despite their incredible capacity for violence, pyroclastic flows are also capable of producing mesmerizing, awe-inspiring beauty.
Birth of an Ocean: The Evolution of Ethiopia's Afar Depression. "Formation of an ocean is a rare event, one few scientists have ever witnessed. Yet this geophysical nativity is unfolding today in one of the hottest and most inhospitable corners of the globe." [Via]