Roy Chapman Andrews and the Kingdom of the Cretaceous Skulls

According to pop-culture, one of the most well-known adventurers and archaeologists in movie history, Dr. Henry Walton "Indiana" Jones, was loosely based on the real naturalist, adventurer and mammologist Roy Chapman Andrews.

"Roy Andrews Chapman on Kublai Khan" (ANDREWS 1921).

Roy Chapman Andrews (1884 -1960) was an American explorer, adventurer, naturalist, mammologist and later director of the American Museum of Natural History.
 
In his youth, he financed his study by offering services as a taxidermist, a self-taught skill. After graduation, he tried to get a job at the Natural History Museum, but there were no positions vacant. Chapman did not surrender and responded that he was even willing to clean the floors if this could him bring into the Museum.
Surprised by such enthusiasm, he was hired as a janitor and assistant taxidermist. Maybe to mock him in a friendly way, he was assigned every morning to mop the floors in the taxidermy studio; the afternoons were then devoted to real taxidermy.

By hard work Andrews managed to get some attention and he was granted a raise in salary, a full-time job as a taxidermist and asked to guide guests in the Museum. In 1907 he was sent on his first expeditions. A whale carcass was washed ashore of Long Island and the Museum hoped to recover the skeleton. Chapman and a colleague were sent to the site, where they discovered that a storm was slowly covering the carcass with sand. For two days they fought the cold sea and the icy wind, only after a week and with the help of local fishermen, the skeleton could be recuperated.

Andrew visited Japan and China, where he collected animals. In 1920 he convinced paleontologist and museum president Fairfield Osborn to finance an expedition into Asia in search of fossils of the early ancestors of major mammalian lineages, including humans. The expedition had a quite racial undertone, intended to demonstrate that the white race had no connection to Asian races, regarded at the time as inferior.
 
Between 1922 and 1939 Andrews and his team carried out five expeditions into previously poorly mapped or unknown areas of Central Asia, a vast desert plagued by blizzards, sandstorms, snakes, flash floods, bandits, civil war and an insecure political equilibrium.
The goals of the expeditions, carried out with an odd combination of early automobiles and camels, was to recover geographical, archaeological, botanical, zoological and geological information, but especially fossils of early hominids.
  "Relief map of Mongolia showing routes, Central Asiatic Expeditions, 1922-1930.", from ANDREWS 1932.
 "Camel and motor car tires" and "Andrews and Tserin at Hatt-In-Sumu, 1928" from ANDREWS 1932.

One of the most important discoveries of the expedition was achieved by chance - Chapman got lost in the monotonous plains and asked direction to a military outpost, meanwhile the photographer of the team, John B. Shackelford, stumbled upon a cliff edge, where he noted some fossil bones. They discovered bones of dinosaurs and mammals, and also an egg, thought to be from a bird. Only hours after the discovery of the site the expedition was forced to turn back - winter was approaching fast in the Gobi - but they decided to return the next years. "The Flaming Cliffs of Djadokhta" (Southern Mongolia), type locality of the Upper Cretaceous Djadoktha Formation, from BERKEY & MORRIS 1927.In the cliffs of red glowing sandstone, named appropriately by Chapman "Flaming Cliffs", they discovered what would become part of the history of palaeontology: various previously unknown dinosaur species - like the gryphon lookalike Protoceratops, or the birdlike Velociraptor, but most scientifically spectacular - rare bones and skulls of Cretaceous mammals, like Zalambdalestes, Djadochtatherium, and Deltatheridium, and oddly enough clusters of large fossil eggs. Eggs of dinosaurs were extremely rare, previous of Chapman only one site on the French Riviera was known with such fossils.
  "The first nest of dinosaur eggs, discovered by Georg Olsen at Shabarakh Usu in 1923. Two eggs and part of another are shown lying on the surface. the small sandstone ledge in the background was removed intact and sent to the Museum. In the center of the block of stone thirteen other eggs were discovered, 1923", from ANDREWS 1932.

Roy Chapman Andrews was a gifted storyteller. He published various accounts of his expeditions and loved to present himself as an adventurer. In his 1935 book, appropriately titled "This Business of Exploring", he wrote:

"I was born to be an explorer...There was never any decision to make. I couldn't do anything else and be happy."

There are various similarities to be spotted between Indiana Jones and Roy Chapman Andrews. Indiana Jones is introduced in the first movie "The Raiders of the Lost Ark" (1981) venturing to Nepal, like Andrews ventured in the Far East. Jones most recognized attributes comprises a 38 colt revolver and a fedora hat. Various expedition photos of Andrew show him with a broad rimmed hat and during expeditions he loved to hunt animals. Once he used his pistols also to defend the expedition from bandits.
However, both producer George Lucas and director Steven Spielberg claim that their fictional character is based mostly on their impressions of matinée serials and pulp magazines of the 1930s-1940s. There is no official confirmation that Indiana is based on a single or a true historic character. However, Andrews (and many other naturalists and explorers of the 18th and 19th century) without doubt influenced by their discoveries, accounts and especially books the general view and love of the public for adventurers. In a certain way, Andrews became part of the Indiana Jones universe (and let us admit, who was not inspired a bit by the Indy-style?)

Bibliography:

ANDREWS, R.C. (1921): Across Mongolian Plains - A naturalists account of China's "Great Northwest". D. Appleton & Company: 276
ANDREWS, R.C. ed. (1932): The New Conquest of Central Asia - A narrative of the explorations of the Central Asiatic Expeditions in Mongolia and China, 1921-1930. Natural History of Central Asia Vol.I.; The American Museum of Natural History New York: 678
ANDREWS, R.C: (1935): This Business Of Exploring. G.P. Putnam´s Sons, New York: 288BERKEY, C.P. & MORRIS, F.K. (1927): Geology of Mongolia - A reconnaissance report based on the investigations of the years 1922-1923. Natural History of Central Asia Vol.II; The American Museum of Natural History New York: 474
GALLENKAMP, C. (2001): Dragon Hunter - Roy Chapman Andrews and the Central Asiatic Expeditions. Penguin Group, New York: 344NOVACEK, M. (2002): Time Traveler: In Search of Dinosaurs and Ancient Mammals from Montana to Mongolia. Farrar Strauss and Giroux: 352

Volcanoes - myths: North America

The Cascade Range on the west coast of the U.S. is not only characterized by earthquakes and their stories, but especially by volcanoes and them too became incorporated in local legends.

Many mountains and areas were feared by local tribes. The Canadian artist Paul Kane who visited Mount St. Helens, in a phase of activity since 1847, wanted to approach the mountain, but was unable to find any local guide

"this mountain has never been visited by either whites or Indians; the latter assert that it is inhabited by a race of beings of a different species, who are cannibals, and whom they hold in great dread."

Other stories recorded by ethnologists tell of displacing encounters "Sometimes people would hear three whistles, and soon stones would begin to hit their lodges. Then they knew that the giants were coming."
Also Spirit Lake was named after an old tradition involving evil spirits and therefore a place to avoid - according to this myth the salmons found in the lake are the transformed ghosts of evil people.

Fig.1. Cascade Range Volcanoes from the U.S.G.S.

This caution was maybe influenced by the experience of eruptions of the Cascade volcanoes in prehistoric times.
The Klamath people of Oregon tell of the time when the chief of Above World - called Skell- and the chief of Below World - called Llao- decided to settle the dispute which of them was stronger. For many days the fight raged over the land, the two adversaries' hurled rocks and flames at each other and soon darkness covered the land. To better see his adversary Llao decided to climb on the highest mountain he could find - the ancient volcano Mount Mazama - but as soon he reached the peak the mountain collapsed with terrible thunders and hurled him back into his underworld domain. The large hole that remained was then filled up with water and became known as Crater Lake.

An eruption in 1800 at Mount St. Helens, known by the locals as Tah-one-lat-clah - "the Fire-Mountain" caused most concern, the Spokane Indians of eastern Washington thought that "the world was falling to pieces" and the Kalispel of northern Idaho, who remember a rain of "cinders and fire", supposed "that the sun had burnt up, and that there was an end of all things."

Other mountains were also regarded as dangerous or inhabited by malevolent spirits. According to one legend once Mount Baker, known previously as Komo Kulshan, one day got so mad that a big piece fell off and slid way down the mountain, causing a big fire and lots of noise.
Mount Rainier, or Tacobud, also one day take a breath so deep that she burst her blood vessels. All over her body, rivers of blood gushed forth and flowed down her sides. Additionally Mount Tacobud was even inhabited by a terrible flood causing monster, which however was finally defeated by some mighty warriors.
Mount Hood, or Wyeast, was also a mountain haunted by evil spirits who "became so angry that they threw out fire and smoke and streams of hot rocks..[] and caused "rivers of liquid rock [that] ran toward the sea, killing all growing things and forcing the Indians to move far away." Unfortunately this time the great chief, that battled the spirits, by scarifying his life was only capable to entrap them, so it is still possible that they will return.

Even if some stories resemble the description of an eruption followed by pyroclastic flows and ash clouds, caution must be adopted to ascribe every myth to a specific and real eruption. Many volcanoes erupted thousand of years ago (like Mount Baker-6.000 years, Mount Rainier- 2.000 years or Mount Mazama- 6.000 years) and it is hard to imagine that oral traditions were passed unmodified trough so many generations and changing cultures in such vast time periods.
Still it is possible that some legends were really inspired by relatively recent eruption like on Mount Hood or Mount St. Helens and that these myths were subsequently adopted to other, maybe similar looking, mountains or regions.

Fig.2. Cascades Eruptions During the Past 4000 Years, from the U.S.G.S.

Not only active or dormant volcanoes, also extinct volcanoes and their landscape influenced the mythology of North America.

The Devils Tower is the eroded neck of a volcano located in north-eastern Wyoming. The name assigned to the monolith by several of the local tribes mention surprisingly often the bear - like Bear's House (Cheyenne, Crow), Bear's Lair (Cheyenne, Crow), Bear's Lodge (Cheyenne, Lakota), Bear's Lodge Butte (Lakota), Bear's Tipi (Arapaho, Cheyenne) and Grizzly Bear Lodge (Lakota).
Two Indian tribes living in the vicinity have slightly different stories accounting for its unique shape, but both involve a group of people being pursued by a giant and angry bear. Exhausted the Indians appealed to their deity for help, suddenly the ground on which they stood raised to the sky, forming a smooth pillar. The bear tried to climb the pillar; the claw marks (a classic example of columnar jointing) made by the bear as he tried to reach them are still visible today.

In California the outcrops of volcanic obsidian glass were an important resource for tool making and considered a gift by spirits or ancient heroes. According to one myth an enormous eagle or condor, the spirit Milili, once scattered all around over California pieces of obsidian, which shattered on impact on the ground. Maybe this could explain the chaotic appearance of some of the ancient lava flows from which obsidian was gathered.

The Wintu Indians of northern California once didn't possess obsidian and therefore their weapons were not much useful to hunt deer. One day the great hunter Adder arrived, who possessed such an extraordinary weapon made of this particular volcanic rock that he managed to kill many deers in just one day. The Wintu hunters became envious, and so they asked Ground squirrel to steal one of the arrows of Adder. Ground squirrel managed to extract a piece of obsidian from one of the hunted deer and run away, but Adder soon noticed the thievery and set the world in fire. Ground squirrel escaped and dropped his load where today is located Glass Mountain near Mount Shasta- however the piece of obsidian carried on his back burned his skin so bad that still today his descends display a black mark on their back.

References:

CASHMAN, K.V. & CRONIN, S.J. (2008): Welcoming a monster to the world: Myths, oral tradition, and modern societal response to volcanic disasters. Journal of Volcanology and Geothermal Research 176: 407-418
VITALIANO, D.B. (2007): Geomythology: geological origins of myths and legends. In Piccardi, L. & Masse, W.B: (eds): Myth and Geology. Geological Society, London, Special Publications, 273: 1-7

May 18, 1980: Tah-one-lat-clah or St. Helens

In the years 1792 to 1794 the crew of the "H.M.S. Discovery" under the command of captain George Vancouver was surveying the western coast of the North American continent, when they in October 1792 spotted a mountain and named it after the British diplomat Alleyne FitzHerbert, 1st Baron St. Helens (1753-1839).
The origin of Saint Helens was however discovered by naturalists only in 1835, when a minor eruption revealed its volcanic nature. First geologic studies were carried out since 1841, when an expedition of the U.S. Army lead by Charles Wilkes reached the volcano; the summit was finally conquered in 1853 by newspaper editor Thomas J. Dryer. In November 1842 the missionary Josiah Parrish experienced an ash rain and earthquakes generated probably by the 130km distant St. Helens. This phase of activity lasted until 1857.

Fig.1. Painting by Canadian painter Paul Kane Mount St. Helens erupting at night after his 1847 visit to the area.

However the local tribes know well the character of these volcanoes, St. Helens was called by the Klickitats the Loo-Wit Lat-kla - "Keeper of the Fire" or Louwala-Clough - "One from Whom Smoke Comes" and also Tah-one-lat-clah - "the Fire- or Smoking-Mountain". According to their legends, the mountain was once the beautiful princess Loo-Wit, who was disputed by two warriors in a battle of fire and smoke which buried entire villages and forests. To end the battle all three were transformed in mountains: the beautiful and shy princess became the symmetrical, ice covered St. Helens; the two angry warriors became the clunky Mount Hood in the south and Mount Adams in the west. This myth was possibly inspired by the observation of a prehistoric eruption of one of the mentioned volcanoes, but there are also direct eyewitnesses' reports: in 1800 the Sanpoil and Spokan Indians told to the first missionaries and traders visiting the area of an eruption occurring on St. Helens.

"The people called it snow… The ashes fell several inches deep all along the Columbia and far on both sides. Everybody was so badly scared that the whole summer was spent in praying. The people even danced — something they never did except in winter.
They didn't gather any food but what they had to have to live on. That winter many people starved to death."
(Oral traditions originally recorded by anthropologist Verne F. Ray in the late 1920s from the Sanpoil and Nespelem Indians of northeast Washington)

Minor eruptions with small explosions and lava flows occurred again in 1898, 1903 and 1921. It was this apparent tranquillity that lead until 1980 to believe that many of the volcanoes of the Cascades were dormant and not threatening, especially one of the youngest and smallest of them - like St. Helens.
In 1969 geologists Dwigth Crandell warned during a congress in San Francisco that the continental volcanoes of North America were still poorly studied and monitored, and much more active than previously assumed. Based on dated deposits of past eruptions, Crandell published with Donal Mullineaux a paper in which he warned that "the scheme of activity of St. Helens led to the assumption that it is possible to postulate an eruption in the next 100 years and maybe even before the end of this century".
In March 1980 finally a monitoring system was installed on St. Helens, also in response to increased interest of the volcanoes located along subduction zones, as is the Cascade Range, after a surprising destructive eruption in the sixties of the Arenal in Central America.
The system registered from the very beginning onwards an increased seismic activity, until end of March earthquakes with a magnitude of 4 happened periodically, on March 27, an explosion occurred - it was now clear that St. Helens had entered a new eruption phase. The volcano became intensively monitored, in April the northern flank begun to rise, probably by intruding magma inside the mountain, an eruption was impending and therefore the area around the volcano was closed to the public.

On Sunday May 18, at 8:32 an earthquake of magnitude 5.1 triggered one of the largest landslide-avalanche ever to be recorded (estimated 2.8 cubic kilometres of rocks and ice) on the northern slope of the mountain, followed by a gigantic explosion. In just 60 seconds the mountain shrinked from 2.950m to 2.549m, 600 square kilometres were devastated by a 600°C hot pyroclastic density current and the burst of the explosion. The melting glacier ice and the overspill of Spirit Lake caused lahars that devastated the valley of the Toutle Rivers.



Despite the delimitated danger zone, 57 people were killed, many of them scientists studying the active volcano inside the zone - nobody expected that the eruption would occur so fast and so furious. Notable the story of David Johnston, U.S.G.S. geologist. Johnston was well aware of the risk of being with his observation station so close to the mountain, but he stayed on there right up to the moment of the eruption - his last recorded words and the first mention of the eruption:

"Vancouver, Vancouver, this is it!".

It is thanks to his work and many others that the eruption of St. Helens is one of the best documented in history. Two geologists, Dorothy and Keith Stoffel, were overflying St. Helens when it erupted:

"The whole north side of the summit crater began to move as one gigantic mass,…[] The entire mass began to ripple and churn without moving laterally. Then the whole north side of the summit began sliding to the north along a deep-seated slide plane."

Also many reporters, hikers and volcano enthusiast, located outside the danger zone, documented the eruption with photographs or descriptions.

This video created with photographs taken by Gary Rosenquist, stationed at 18km northeast of St. Helens in the morning of May 18, shows the dynamics of the slope collapse and the pyroclastic explosion. The first photo was taken at 8:27, in the next 6 minutes he take a dozen photos before he escaped the approaching pyroclastic current. The landslide previous the eruption is well visible as the block moves downward, followed by the pyroclastic flow projecting first upward, then sideward and surpassing the landslide.



The eruption at St. Helens was only a single event in the long history of the Fire Mountains of the Cascade Range, like in the fossil forest of Yellowstone many times the landscape was destroyed, reborn and modified by volcanic eruptions. Today St. Helens is monitored and the area protected to understand the colonization by animals and plants of a devastated landscape - a new chapter to be written in the geologic record.



Bibliography:

DAVIS, L. (2008): Natural Disasters. Facts on File Science Library. Infobase Publishing: 464
CRANDELL, D. R. & MULLINEAUX D, R., (1978): Potential hazards from future eruptions of Mount St. Helens, Washington: U.S. Geological Survey Bulletin 1383-C: 26
GUNN, A.M. (2008): Encyclopedia of Disasters - Environmental Catastrophes and Human Tragedies. Vol.1. Greenwood Press, London: 733
LEWIS, T.A.(ed) (1985): Volcano (Planet Earth). Time-Life Books: 176

Online Resources:

TOPINKA, L. (03.01.2011): Volcanoes and History. Cascades Volcano Observatory, Vancouver, Washington. (Accessed 17.05.2011)
WATSON, J. (25.06.1997): Mount St. Helens Volcano. (Accessed 17.05.2011)

The fossil forests of Amethyst Mountain

The fossil forests of Specimen Ridge and Amethyst Mountain, both situated in the Yellowstone National Park, are peculiar because of many preserved trees still found as upright trunks and stumps emerging from the sediments.
The geologist, anthropologist and artist Dr. William H. Holmes was the first to study the outcrop of Amethyst Mountain and published his observations in 1878:

"As we ride up the trail that meanders the smooth river bottom [the Lamar River] we have but to turn our attention to the cliffs on the right hand to discover a multitude of the bleached trunks of the ancient forests. In the steeper middle portion of the mountain face, rows of upright trunks stand out on the ledges like the columns of a ruined temple. On the more gentle slopes farther down, but where it is still too steep to support vegetation, save a few pines, the petrified trunks fairly cover the surface, and were at first supposed by us to be shattered remains of a recent forest."

Fig.1. Pencil drawing ca. 1879 by Holmes of the outcrop of Amethyst Mountain, National Archives.

Fig.2. Two fine specimens of fossil tree trunks of Pilyoxylon aldersoni in the fossil forest on a steep hillside of Specimen Ridge, exposed by erosion of the basic breccia in which the stumps and roots are firmly embedded. Nearby a hoodoo, showing the character of the breccia and the manner in which it has been deposited. Circa 1890. Figure 2, U.S. Geological Survey Folio 30, USGS Photo Library.

Holmes studying the outcrops realized that the silicified stumps are distributed in various levels (more than fifty are today recognized) and embedded in volcanic deposits like ash, mud flows and breccias. These deposits provided also an explanation of the remarkable well preserved structure of the wood: from the rocks the silica was solved by the percolating water and substituted the organic matter of the wood. Inside of some hollows trunks even geods with crystals of amethyst formed and the name of the mineral was adopted previous of 1870 to the entire site, unfortunately most of these specimens were removed by collectors already in the late 19th century.
The upright position and the well preserved roots are a sign that the trees became embedded in situ, covered by ashes, mudstone, breccias and conglomerates during a volcanic eruption. There are also signs of fluvial reworking of the deposits, many trees rooted in tuffaceous sandstones, interpretated as paleosoils, and conglomerates deposited by a braided river system.

Fig.3. Schematic profile of Amethyst Mountain as imagined by Holmes and published in "Fossil forests of the volcanic tertiary formations of the Yellowstone National Park. Bull U.S. Geological and Geographical Survey of the Territories Vol.5.(1), 1879-1880"

A modern example possibly resembling the environment of formation of the petrified Yellowstone forests was the landscape after the eruption of Mount St. Helens in 1980. Here a violent eruption razed down large areas of the forest surrounding the mountain, leaving behind stumps that were buried under pyroclastic flows and lahars.
Today, more than 30 years later the effects of the explosion are still visible, even if a new forest has begun to colonize the devastated area. Subsequent research showed that St. Helens experienced many eruptions in the Holocene, repeatedly the area was devastated and repeatedly the area was reconquered by nature.

Also in Yellowstone the buried forest was destroyed, entombed in the volcanic deposits and the new formed landscape colonized again by a new forest. The time period involved in these cycles was however at the time of Holmes unclear, however the perfectly preserved tree rings inspired geologists to try to estimate how much time was involved in the growth phase of the plants and finally in the formation of the entire sedimentary succession:

"Pine trees of the types represented in the fossil trunks require 200 or 300 years to reach maturity, and redwoods may require from 500 to 1,000 years. Twelve or more of these forest levels have been found. By multiplying this number by the minimum age of the trees (200 years) we shall have 2,400 years, and by multiplying it by the maximum age of the redwood (1,000 years) we shall have 12,000 years as the possible time during which these forests flourished. It is possible that the truth lies somewhere between these extremes."
(KNOWLTON 1921)

Glacial erosion on Specimen Ridge and Amethyst Mountain showed that the volcanic activity was older than the ice age and therefore geologist inferred a tertiary age, so Knowlton in 1921 summarizes:

"After the Cretaceous period, there was a time of great volcanic activity, which appears to have lasted until perhaps the beginning of the glacial epoch."

Today the sediments are dated thanks to modern methods into the Eocene. The events at St. Helens provided also a possible time period for the formation of the fossils, well preserved wood was found in centuries old lahars of the volcano with silica beginning to substitute the organic matter, in some cases even after 36.000 years the fossilisation was not completed.

However I have to note that this scenario is only a theory and there is an alternative explanation: the forest was buried in a worldwide flood send by a magic, invisible creature living in the sky that so loved its own creation that it decided to destroy it to punish a single species of upright, naked ape, with the exception of a single family dedicated to inbreed - much more plausible than a series of boring volcanic eruptions...

Online Ressource:

COFFIN, H.G. (1976): Orientation of trees in the Yellowstone Petrified Forests. Journal of Paleontology. Vol.50(3): 539-543. (Accessed 16.05.2011)
KNOWLTON, F.H. (1921): Fossil Forests of the Yellowstone National Park. USGS Monograph 32: 651-791. (Accessed 16.05.2011)
VINEY, M. (2008): The Virtual Petrified Wood Museum. (Accessed 16.05.2011)

The Younger Dryas impact hypothesis

The cause(s) that led to the extinction of most of the larger mammals that roamed the Pleistocene world are still today unknown. Many different hypotheses were proposed, from human overkill to climate change, but more unusual was an idea largely publicized in 2007.

Geophysical studies presented in spring 2007 suggested that perhaps an extraterrestrial bolide vaporized in the Earth's atmosphere caused the extinction of the North American Megafauna some 13.000 years ago.
In 2009 this hypothesis seemed to be further confirmed by subsequent findings. This and other interdisciplinary research presented various sedimentological features found in peat layers at nine excavated sites of the North American continent and one site in Belgium and thought to be associated with impacts of meteorites on earth.

Fig.1. Profiles of sites in North America with proposed sedimentological evidences for an impact event some 12.900 years ago. The diagrams show the concentration of magnetic particles, microspheres, particles of coal and glass and some elements rare in the earth's crust but common in meteorites (such as iridium, chromium and nickel). The highest values are apparently found in a distinct single thin layer, after FIRESTONE et al. 2007.

1) An increased concentration of iridium, a rare element in earth's crust but common in meteorites.

2) Metallic particles and grains, also carbon microspheres concentrated in a thin layer, interpreted as remains of the impacted meteorite and the recrystallized molten rocks of the bolide and crust.

Fig.2. and 3. The metallic micrometeorites with a diameter between 100 to 150 µm found in one of the profiles (Blackwater Draw) showed a high content of titanium and nickel typical for extraterrestrial material (FIRESTONE et al. 2007), also shown the carbon microspheres interpretated as the remains of the molten and recrystallized bolide.

3) A particular and rare modification of carbon - Lonsdaleite - in shape of microscopic nanodiamonds with a hexagonal crystalline structure formed only under very high pressure as experienced during an impact.

4) Another exotic modification of carbon, the Buckminsterfullerene or buckyballs, a modification of carbon that supposedly can be created only under great heat conditions.

5) Dark layers of peat or sediments rich in organic matter were interpreted as the remains of burned vegetation by megafires ignited by the heat of the impact.

6) Recovered Pleistocene bones of mammoth and bison showed features that were interpreted as direct effects of the explosion - small, 2 to 3 mm in diameter, holes in the bones with a burned halo and penetrated magnetic particles with a high content of iron and nickel of unusual isotopic composition.

To explain the lack of the most compelling evidence - the impact crater- it was suggested that the bolide exploded above or on the Laurentide ice shield, leaving behind no visible trace.
7) An alternative suggestion positioned a debris field in the Carolina Bay area along the south-eastern coast of the United States. The Carolina Bays include thousands of circular to elliptical depressions across the coastal plain of still unknown origin (some authors suggested even spawning fish).

The most intriguing conclusion of the Younger Dryas impact hypothesis: The heat released and the shock waves of the impact caused the extinction of the North American Megafauna and the annihilation of the Clovis-culture possibly in two ways, by directly killing animals and igniting large scale firestorms and in a second moment by the partial melting of the ice shield of North America and Greenland. The large amounts of fresh water released in the Atlantic Ocean caused an arrestment or a slowdown of the warm Gulf Stream, starting a 1.500 years long climatic reversal recognized especially in Europe as Younger Dryas stadial (12.900-11.600 cal BP), an important phase of cooling recognized in glacier advances and vegetation shift.

Fig.4. The isotopic values as proxy of climate recovered in ice cores from Greenland show a distinct phase of climatic reversal between 12.900 and 11.600 years ago. The sudden beginning of this period named Younger Dryas stadial is still poorly understand, the influence of changing patterns of the marine currents in the Atlantic at the end of the Pleistocene are the most suggested and likely triggers of such an abrupt climate change (Greenland Ice Core Chronology 2005 released 10. March 2006).

The hypothesis experienced a positive and large attention in the popular media but got mixed reception from earth scientists during it´s official presentation in May 2007 at the congress of the American Geophysical Union.
The meteorite idea was however not completely new and already published in 2001 and in 2006 even in a own book - however with some pseudoscientific implications like glacial landscapes with drumlins or the North American Great Lakes as the direct results of the impact.

Also focusing only on the research published in 2007 soon problems arouse. For example the methods used to identify some of the most compelling impact evidence, like the nanodiamonds, were questioned because the results of the analyses were explainable also by other, more earthly, materials.
More important - the impact hypothesis could only explain a local decline and extinction event for the American continent in a very short interval, maybe in few decades or centuries. However dated fossils seem not to support a unique and sudden extinction as proposed by this and many other catastrophist hypotheses. In a survey on 4.532 archaeological sites in Europe and Siberia and 1.177 dated remains of mammoth and mastodons in Europe, Siberia and North America the dates scatter between 45.000 to 12.000 years.
Estimating the development of the population of single species there seems to be various phases of increase and decline in numbers of individuals. The woolly mammoth for example reaches a population maximum some 16.000 to 15.500 years ago, this phase is followed by a slow decline 14.500 to 13.500 years ago, however isolated populations survived on islands and in northern regions of Asia even until historic times.

Apart of these general critics in 2011 a paper By PINTER et al. focused explicit on the single evidences as presented in 2007 and subsequent years and concluded that most of the claims can not be reproduced and the few reproduced evidences are not unequivocally related to an impact of an extraterrestrial bolide:

1) The iridium concentration was not measured in the bulk sediment but on single fragments or spherules thought to be of impact origin - this could falsify the apparent peak in the stratigraphic column. On some studied sites the concentration of iridium in the supposed Dryas interval was also surprisingly low. Despite the methodological error, these contradicting results are imputable to diagenetic alteration of the sediments and the iridium concentration is more likely of terrestrial origin.
More notable subsequent research failed to reproduce the single iridium peak.

2) Some of the carbon spherules resulted to be fungal spores or coprolites of arthropods. Subsequent research could not reproduce a peak or concentration of micrometeorites in a single layer, but the particles resulted to be distributed homogenous in the stratigraphic column, as more likely explained by the common background sedimentation from the interplanetary space occurring during geological times.

3) The supposed nanodiamonds resulted by further and more detailed investigations to be amorphous to polycrystalline carbon aggregates as produced during common wildfires, the presence of the particular carbon modification Lonsdaleite could not unequivocally proven in the sediments.

4) The presence of buckyballs was questioned because of methodological problems already in the original research and later investigations could not reproduce the results. Despite the dubious presence of the fullerenes, it is known that small amounts of this carbon modification can be produced by common wildfires, so even if buckyballs will be found, these are not unequivocally evidence of an impact.

5) Sediments rich of organic matter are not necessary produced by wildfires; common depositional environments like swamps can also produce thick layers with encoaled plant remains. Some proposed impact-related dark layers, supposedly rich of organic matter, resulted even to be coloured not by organic remains but by minerals. There is today no unequivocally evidence that the layers are connected to any wildfires after an impact.

6) Some of the bones with the supposed fragments of the bolide resulted to be older by nearly 20.000 years than the previously specified impact date. The fragments in the bones were not reanalyzed after the first claims and doubts arouse of the proposed origin.
It seems unlikely that such minuscule and fragile particles could penetrate earth's atmosphere and still impact on such a hard material as are the bones. In alternative it is well possible that the discovered particles are more likely diagenetic iron concentrations.

7) The explanation of the Carolina Bays as debris field is not supported by any discovery of extraterrestrial material in the area; also relative dating efforts showed that these depressions were formed probably during a long time interval. So if these features still remain mysterious an impact origin seems the most unlikely cause of origin.
Even radiocarbon ages achieved by the impact supporters showed significant fluctuations in the ages of formation, ranging from 6.500 to 700 years ago. This lead to the excuse that "the impacting object was ejected by a recent near-Earth supernova in which case carbon [was] enriched" modifying the radiocarbon age of the sediments.
Realizing the improbability and problems of such claims the Carolina Bays were rejected as evidence by most impact proponents.

The Younger Dryas Impact Hypothesis was adopted mainly by non earth-sciences related researchers and especially the mass media, who dedicated to the scenario even various TV-shows. Even if it was stated that some of the results were preliminary, it is still surprising how catastrophic theories are accepted uncritically by popular media.
However three years later it seems that most of the proposed evidence for the Younger Dryas Impact Hypothesis could not be reproduced by other teams and were evidence is available there are terrestrial, non impact related, interpretations possible.

Bibliography:

BECKER (2007): Abstract: The End Pleistocene Extinction Event - What Caused It? Eos Trans. AGU, Abstract PP41A-03
BECKER (2007): Ice Age Impact. mp3 (4MB). (Interview by the Canadian Broadcast)
FIRESTONE, R.B.; WEST, A.; KENNETT, J.P.; BECKER, L.; BUNCH, T.E. et al. (2007): Evidence for an extraterrestrial impact 12,900 years ago that contributed to the megafaunal extinctions and the Younger Dryas cooling. Proceedings of the National Academy of Sciences of the United States of America 104(41): 16016-16021
KENNETT, D.J.; KENNETT, J.P.; WEST, A.; WEST, G.J.; BUNCH, T.E. et al . (2009): Shock-synthesized hexagonal diamonds in Younger Dryas boundary sediments. Proceedings of the National Academy of Sciences of the United States of America 106: 12623-12638
KERR, R.A. (2007): Mammoth-Killer Impact Gets Mixed Reception From Earth Scientists. Science 316: 1264-1265
KERR, R.A. (2008): PLANETARY IMPACTS: Did the Mammoth Slayer Leave a Diamond Calling Card? Science Vol.323 : 26
LEVY, S. (2006): Clashing with Titans. BioScience Vol. 56(4) : 292-298
PINTER, N.; SCOTT, A.C.; DAULTON, T.L.; PODOLL, A.; KOEBERL, C.; ANDERSON, R.S.; ISHMAN, S.E. (2011): The Younger Dryas impact hypothesis: A requiem. Earth Science Reviews. Article in Press
UGAN, A. & BYERS, D. (2007): Geographic and temporal trends in proboscidean and human radiocarbon histories during the late Pleistocene. Quaternary Science Reviews.26: 3017-3440

Online Resources:

MORRISON, D. (2010): Did a Cosmic Impact Kill the Mammoths? (Accessed on 23.04.2011)

April 20, 2010: Deepwater Horizon oil spill

An explosion on the BP-operated Deepwater Horizon oilrig in the Gulf of Mexico on April 20. 2010 and the subsequent oil spill for nine months has become one of the second-most presented, discussed and publicized environmental catastrophe in the last decades (the first would be Chernobyl).

Politicians, authorities and experts referred to the accident as "unprecedented" and were insecure of the amount of oil spilled, the area affected and the effects of the oil on the marine environment. One of the surprising consequences of an oil leak in 1.200m depth were large subsurface oil plumes, whose existence were first doubted or even denied.

Fig.1. The oil slick as seen from space by NASA's Terra satellite on May 2. 2010 (image from Wikipedia).

This posed a major problem in the estimation by traditional methods - areal or satellite images - of the oil amount released into the gulf.

The oil on the surface was more visible and BP tried to deny it, entrap it, burn it or disperse it with chemicals, however despite the efforts on April 29. first oil traces were spotted on the US-coast, which caused an immediate and immense media response.



The Deepwater Horizon accident is however not completely unprecedented, in 1979 a blowout from the Ixtoc I platform in the Bay of Campeche released for nine months in sum 454.000-480.000 tons of oil into the water - the world's largest peacetime oil spill until the Deepwater Horizon accident with estimated 500.000-627.000 tons.
Many of the effects and problems observed at the Ixtoc I accident however were seemingly forgotten, as it seems that today the consequences of the Deepwater Horizon accident are already forgotten.

Bibliography:

JERNELÖV, A. (2010): The Threats from Oil Spills: Now, Then, and in the Future. AMBIO 39:353-366
SAFINA, C. (2011): The 2010 Gulf of Mexico Oil Well Blowout: A Little Hindsight. PLoS Biology 9(4): 1-5

April 18, 1906: The Great San Francisco Earthquake

"San Andreas Fault
Moved its fingers
Through the ground
Terra cotta shattered
And the walls came
Tumbling down

O, promised land
O, wicked ground
Build a dream
Tear it down

O, promised land
What a wicked ground
Build a dream
Watch it all fall down"
"San Andreas Fault" sung by Natalie Merchant

 

One of the firsts to note something unusual where the sailors of the transport ship "Wellington" entering the bay in early morning of April 18. 1906, the captain reports that the ship "shivered and shook like a springless wagon on a corduroy road" even if the sea was as "smooth as glass".
At the shores of Ocean Beach the worker Clarence Judson was taking a swim in the sea when he was grabbed by a strong current and sucked into the deep - only with great effort he reached the coast:

"I tried to run to where my shoes, hat and bathrobe lay, but I guess I must have described all kinds of figures in the sand. I thought I was paralyzed. Then I thought of lightning, as the beach was full of phosphorescence. Every step I took left a brilliant iridescent streak. I jumped on my bathrobe to save me."

In Washington Street the police sergeant Jesse Cook observed a terrifying spectacle:

"The whole street was undulating. It was as if the waves of the ocean were coming toward me, billowing as they came..[]"
"Davis Street split right open in front of me, … A gaping trench. . . about six feet deep and half full of water suddenly yawned and sprang up on the sidewalk at the southeast corner while the walls of the building I had marked for my asylum began tottering. Before I could get into the shelter of the doorway those walls had actually fallen inward. But the stacked-up cases of produce that filled the place prevented them from wholly collapsing."

The Geography professor George Davidson awoke from the tumult coming from the street, he grabbed his wristwatch on the desk and noted the length of a first quake - 60 seconds- and the second - again 20 to 40 seconds - and the time that later will be the official date of the great earthquake of San Francisco: 5:12.

Many people were still asleep and killed in their beds, those who escaped gathered in the streets - despite the earthquake most of the city seemed still intact and surprisingly quiet.

In 1906 San Francisco was a great and ambitious, but also corrupt and infamous city with more than 400.000 inhabitants; it had experienced an incredible growth since 1848 thanks to the discovery of gold in the rivers of California. Now it was an important harbour to the Pacific Ocean and modern trade place, many shops sold the newest technologies in cameras and film equipment. The earthquake of San Francisco will become the first natural disaster of its magnitude to be so well documented by photography and motion picture footage (even in colour).
This growth and achievements were however possible only by cheap and fast construction methods and so most buildings in San Francisco were not exceptionally stable and made of wood.
San Francisco had burned to the ground six times in the past century and experienced stronger earthquakes in 1865 and 1868 when 30 people died. However the modern automatized fire department and equipment - horse driven and steam powered water pumps - was believed to be capable to fight every fire.Fig.1. "Earthquakey Times", a caricature by Ed Jump of the October 8. 1865 earthquake in San Francisco. While he was working as a newspaper reporter in San Francisco, Mark Twain experienced the earthquake which he describes in his 1872 book "Roughing It."
"It was just after noon, on a bright October day. I was coming down Third Street. The only objects in motion anywhere . . . were a man in a buggy behind me, and a [horse-drawn] streetcar wending slowly up the cross street. . . . As I turned the corner, around a frame house, there was a great rattle and jar. . . . Before I could turn and seek the door, there came a terrific shock; the ground seemed to roll under me in waves, interrupted by a violent joggling up and down, and there was a heavy grinding noise as of brick houses rubbing together. I fell up against the frame house and hurt my elbow. . . A third and still severer shock came, and as I reeled about on the pavement trying to keep my footing, I saw a sight! The entire front of a tall fourstory brick building on Third Street sprung outward like a door and fell sprawling across the street, raising a great dust-like volume of smoke! And here came the buggy-overboard went the man, and in less time than I can tell it the vehicle was distributed in small fragments along three hundred yards of street. . . . The streetcar had stopped, the horses were rearing and plunging, the passengers were pouring out at both ends. . . . Every door, of every house, as far as the eye could reach, was vomiting a stream of human beings; and almost before one could execute a wink and begin another, there was a massed multitude of people stretching in endless procession down every street my position commanded. . . . For some days afterward, groups of eyeing and pointing men stood about many a building, looking at long zig-zag cracks that extended from the eaves to the ground..."

Police sergeant Jesse Cook was the first to report a fire at April 18. in a grocery in Clay Street, some hours later there where already fifty in the entire city. The fire fighters realized horrified that the water pipers in the underground were broken and the hydrants in the city useless. The firestorm rages in the city for three days and will be responsible of 90 percent of the 28.000 destroyed buildings.

The journalist Arnold Genthe is thrilled by the scenery and the devastation caused by the approaching fire, unfortunately he discovers that his camera was damaged during the quake.

"I found that my hand cameras had been so damaged by the falling plaster as to be rendered useless. I went to Montgomery Street to the shop of George Kahn, my dealer, and asked him to lend me a camera. "Take anything you want. This place is going to burn up anyway." I selected the best small camera, a 3A Kodak Special. I stuffed my pockets with films and started out...."
He will take some of the most famous photos in history.

Fig.2. "Looking Down Sacramento Street, San Francisco, April 18. 1906."

The owner of "Hotaling´s Whiskey" in Jackson Streets decides to remain and fight the flames - he pays 80 men to sprinkle 5.000 barrels of whisky with water pumped out from the sewer system. Later he will mock all those who claim that the earthquake was send by god by coining a new advertising slogan:

"If, as some say, God spanked the town, for being over frisky - why did He burn the churches down an save Hotaling´s Whiskey?"

Army troops were soon ordered into the city to help in the fire fighting and prevent panic and looting. The lack of water forced to desperate measures - by blasting of entire quarters to create firebreaks it was hoped to stop the flames, however many explosions ignited even more fires. Despite martial law was never proclaimed, the major authorized policeman and soldiers to shoot looting persons - "Obey orders or get shot" was the grim warning on some improvised signboards.
Guion Dewey, a businessman from Virginia, wandering onto the streets of downtown San Francisco minutes after the quake experienced the best and worst of human behavior, as he later reported in a letter to his mother:

"I saw innocent men shot down by the irresponsible militia. I walked four miles to have my jaw set. A stranger tried to make me accept a $10 gold piece. I was threatened with death for trying to help a small girl drag a trunk from a burning house, where her father and mother had been killed. A strange man gave me raw eggs and milk . . . (the first food I had had for twenty-two hours). I saw a soldier shoot a horse because its driver allowed it to drink at a fire hose which had burst. I had a Catholic priest kneel by me in the park as I lay on a bed of alfalfa hay, covered with a piece of carpet, and pray to the Holy Father for relief for my pain. . . . I saw a poor woman, barefoot, told to "Go to Hell and be glad for it" for asking for a glass of milk at a dairyman's wagon; she had in her arms a baby with its legs broken. I gave her a dollar and walked with her to the hospital. . . .I was pressed into service by an officer, who made me help to strike tents in front of the St. Francis Hotel, when the order was issued to dynamite all buildings in the vicinity to save the hotel. I like him, and hope to meet him again. When he saw I was hurt, which I had not told him, not yet having been bandaged, he took me to his own tent and gave me water and brandy and a clean handkerchief."

The earthquake and the firestorms killed estimated 3.000 to 4.000 people, destroyed 28.000 buildings and the infrastructure of the entire city - but in a surprisingly rush people begun planning and reconstruction work on their homes and life, three year later most of San Francisco was rebuild.

Seismology was still a young scientific discipline at the time of the earthquake in San Francisco, in part as a result of the lack of appropriate equipment like sensible tools to measure the tremors of earth - worldwide there were only 96 seismographs operating, none of these in California. In the aftermath of the disaster, only three days later, the Governor of California announced the formation of the State Earthquake Investigation Commission led by geologist Andrew C. Lawson of the University of California.
The commission concentrated their work on the San Andreas Rift, a local straight valley until them considered of minor interest and mapped only in short sections. For two years Lawson and his team followed the rift along ponds and streams and up and down poison oak-covered hills on foot and horseback, they recognized that the rift followed almost the entire coastline of California for more than 1.000 kilometres. During the April 18. earthquake nearly 480 kilometres of the Earth's surface along the today notorious known San Andreas fault line had ruptured displacing the ground horizontally instead of vertically, as geologists had previously believed to be the source of earthquakes.
The commission will locate the epicentre of the earthquake at the place of the greatest observed displacing on land - however today the epicentre is believed to be situated below the Pacific Ocean, in accordance to the seismic waves coming from the sea as observed by the first eyewitnesses.
Nevertheless this finding led team member Henry Fielding Reid, a geology professor at Johns Hopkins University in Maryland, to propose a new theory regarding the origin of earthquakes. Later dubbed the "theory of elastic rebound" Reid's hypothesis was to have a revolutionary impact on the young field of seismology.

Bibliography:

MORRIS, C. (2006): The San Francisco Calamity by Earthquake and Fire. Librivox
SLAVICEK, L.C. (2008): The San Francisco Earthquake and Fire of 1906. Great Historic Disasters. Chelsea House Publishers: 128
STARR, J.D. (1907): The California Earthquake of 1906. A.M. Robertson, San Francisco

Online Resources:

USGS (2009): The Great 1906 San Francisco Earthquake. (Accessed on 17.04.2011)

27 March, 1964: The Alaska Earthquake

“One day earthquake and thunder decided to explore the world, but doing so they reached only a desolate and dry plateau. Earthquake noted that the land was located much too high in the sky for humans “They will have no food, if there is no place for the creatures of the sea to live in!” Earthquake begun to shake, stronger and stronger, until the earth finally collapsed and the sea inundated the land. Earthquake was satisfied “From here, they will obtain what they need to live, where prairie has become water…. This is what brings to the people life.” Thunder acknowledged what earthquake had done “It is true. So they will survive!” and so they went further north and together they lowered the land and created the western coast.”
The creation of the world according to a legend of the Yurok people (Cascade Range)

In the late afternoon of March 27, 1964 Alaska was shaken for five minutes by one of the strongest earthquakes ever to be recorded in modern times, with a magnitude of 8.3 – 9.2 after Richter (the earthquake was so strong that no seismometer in the affected area recorded it correctly).
The earthquake displaced almost the entire southern coast of Alaska along the Prince William Sound, some areas were raised by 9 meters (30 feet) above the sea level, other dropped below sea level and became inundated later by the sea (maybe the Yurok myth is based on the observation of such a similar environmental change after an earthquake in prehistoric times along the western coast of the U.S.).

The earthquake caused heavy damage on 75% of buildings and infrastructure in the affected area, most in the city of Anchorage, 131 people were killed.
Large fissures opened in the ground when the groundwater liquefied the soil and more than 2.000 landslides and avalanches occurred across south-central Alaska. Buildings in Seattle (Washington) begun to swing by the approaching seismic wave and the ground was measurable deformed even in Florida.

Fig.1. Aerial photographs of destructive landslides and damage in Anchorage, Photo by A. Grantz / image in public domain from the U.S.G.S. Photographic Library.

In some lakes in Alaska the movement of the water catapulted chunks of ice onto the land, causing damage on the surrounding trees up to 9 meters (30 feet) above ground. Unusual water movements, attributed cautiously to the earthquake, were observed in South Dakota and apparently even in Puerto Rico and Australia.
Most remarkable was the generated tsunami, waves higher than usual were observed even along the Japanese coast. The seaport of Valdez was destroyed by a 30 meter high tsunami, 32 people died there. For hours after the earthquake the sea was tumultuous and in the evening with the high tide the reflected waves of the first tsunami inundated the surviving area of the city of Valdez.
Six hours after the earthquake the tsunami reached the coasts of Vancouver Island, one hour later the coast of Oregon and the wave caused damage even in Crescent City and Los Angeles (California). 

Many of these phenomena were studied for the very first time by scientists – only two hours after the earthquake the first geologists arrived to Anchorage.

Fig.2. Alaska Earthquake March 27, 1964. Rockslide avalanche on Sherman Glacier. The source was from the area marked by the fresh scar on Shattered Peak (top center image). The debris displays flowlines and terminal digitate lobes. No marginal dust layer is present. The steep margin, about 20 meters above the clear ice, is due to more rapid melting of the exposed glacier than the ice protected by the debris. Photo by A. Post, August 25, 1965 / Geological Survey.

Bibliography:

Committee on the Alaska Earthquake of the Division of Earth Sciences National Research Council (1968): The Great Alaska Earthquake of 1964. National Academy of Sciences, Washington: 473
GATES, A.E. & RITCHIE, D. (2007): Encyclopedia of earthquakes and Volcanoes. Facts on file science library. 3th ed. New York: 346
WALKER, B. (1982): Earthquake. Planet Earth. Time Life Books: 154

Online Resources:

GATES (2007): U.S.G.S. (21.10.2009): Historic Earthquakes - Prince William Sound, Alaska 1964.