Monat: Mai 2020

Geological Movie Review – „Alien“

When the movie “Alien” was released in 1979, it quickly terrified audiences worldwide. Its unexpected mix of classic horror and science-fiction elements got at first mixed reviews, however, over the years Alien had come to be regarded as one of the best horror-science-fiction films ever made.“Alien“ screenwriters Dan O’Bannon and Ronald Shusett based parts of their script on various older science-fiction movies and tales, like „At the Mountains of Madness“, a science-fiction/horror story published by American author H.P. Lovecraft in 1936. In the story, a team of scientists is hunted and killed by ancient creatures resembling fossil animals. Lovecraft apparently based this part of his story on the real discovery of fossil archaeocyathids in Antarctica made in 1920 by geologist William Thomas Gordon. Archaeocyathids are an extinct group of sponge-like creatures believed to be among the oldest animals ever to live on Earth.

Hans Rudolf Giger, Swiss surrealist artist, architect and industrial designer, was hired to create all forms of the Alien featuring in the film, from the egg to the adult. Giger created various versions of the alien life-cycle, like a gigantic egg nest, replaced in the final movie with an egg silo inside a derelict spaceship. The eggs were directly inspired by female reproductive organs, slightly modified to avoid censorship. The facehugger, a parasite attaching to the head of its victim to incubate an embryo, is based on the bones and muscles of a human hand and male genitalia, its springlike tail was added to emphasize its quick movements. The parasitic life-form was an idea of Ronald Shusett. Shusett suggested that one of the crew members be implanted with an alien parasite to explain how the alien life-form, discovered at first as an egg in a derelict alien spaceship, came on board of the mining spacecraft Nostromo. The parasite bursts from the chest of its victim and soon the crew has to deal with the fast-growing life-form hiding in the air vents of the spaceship. The design of the chestburster and the full-grown xenomorph (alien-shaped thing) is based on Giger’s „Necronom IV„, an artwork created in 1976. The surrealist drawing shows a female figure composed of different parts of insects, parts of vertebrates and even fossils. Giger used the fossils of 300 million-year-old crinoids, commonly called sea lilies, on display in the Aathal dinosaur museum as a source of inspiration.

A petrified crinoid. Similar fossils inspired the creature featured in the successful „Alien“ saga.

The earliest known crinoids date back to the Ordovician (some 450 million years ago). Their remains are very common in the fossil record, forming rocks like limestone or dolostone. The skin of echinoderms, including sea cucumbers, sea urchins, crinoids, brittle stars and starfish, is covered with tiny ossicles made of calcium carbonate forming a protective, yet flexible, outer shell. In a similar way, Giger’s Alien is protected by a silicon-based external skeleton. This outer shell is also very useful to contain the acid blood of the creature. Concept artist Ron Cobb added the acid blood as a defense mechanism, making it impossible to kill the Alien without damage to the crew or the spaceship.

In the sequel „Aliens“ a team of space marines enters an Alien hive, the walls resembling Goethite, Grube Eisekaute, Bad Marienberg, Germany.

The life-cycle of the Alien from egg to queen (as introduced in the sequel) resembles the life-cycle of real animals, the Ichneumonidae. The Ichneumonidae is a wasp family preying on insects. An adult female wasp will lay her eggs within a host through a process known as ovipositing. The eggs will grow and develop into larvae, which will feed on their host from the inside-out. Somewhere along the way the host will actually die or be kept in a state very near death until, finally, the little wasp spins a cocoon around and-or within its host, eventually emerging as an adult wasp. A horrified Charles Darwin famously mentions in a letter sent in 1860 to his friend, the botanist Asa Gray, the parasitoid wasp:

» I cannot persuade myself that a beneficent and omnipotent God would have designedly created the Ichneumonidae with the express intention of their feeding within the living bodies of caterpillars… «

In their natural environment, these wasps play important roles in regulating the populations of their insect hosts, and have been used in agricultural crops to control caterpillar pests. Dolichogenidae xenomorph is a parasitoid wasp species named in 2018 after the xenomorph, as „the wasp is also black and shiny like the Alien.“

The graphic representation of the „perfect organism“ earned the visual effects team of „Alien“ a well-deserved Academy Award.

Geological Observations Revolutionized Renaissance Art

» It is their art to stop at every stone and carry out an investigation at every layer of earth! «

Swiss author Rodolphe Toepffer describing geologists

During the Renaissance, the study of common rocks inspired great artists and revolutionized artistic techniques. Italian artist Leonardo da Vinci was one of the first naturalists to both understand the origin of sedimentary rocks and recognize fossils as petrified remains of former living animals. He used his geological insights to improve his paintings and in doing so inspired an entire generation of artists.

The Alps, ca. 1513, red chalk drawing by Leonardo da Vinci. He was fascinated by mountains and called them the “bones of the earth.”

This approach can be seen in da Vinci´s earliest recognized works, dating to 1473. In „The Hills of Tuscany“ or „Landscape with River“, we are apparently standing on the borders of the Apennines, looking down onto a waterfall and the larger valley of the Arno.

The layers of the earth, visible above the waterfall, are depicted in a geologically correct way – thin at the bottom and thick on the top, like the Turbidite sequences found in the Apennines. Together with the lines used to draw the cultivated fields in the Arno valley, the sedimentary layers help to create an three-dimensional effect giving to this landscape a realistic „depth.“ This effect is also helped by the waterfall, which is shown flowing away from the observer in a hydrologically correct manner down the slopes of the mountains into the Arno valley.

Leonardo da Vinci’s sketch of an outcrop.
Outcrop with sedimentary layers as spotted in the Apennines.

Leonardo’s technique was soon adopted by other artists. German painter Albrecht Dürer visited Italy twice to study the perspectival paintings of contemporary Italian architects and artists. Traveling back home, he tried to apply this revolutionary method to his own paintings. One of his drawings shows a quarry, maybe somewhere near his hometown of Nürnberg, displaying horizontal layers of sandstone and thinner layers of marl in a manner similar to da Vinci’s. Using the tectonic fractures as vertical construction lines, Dürer tried here to subdivide the picture like da Vinci and create the illusion of depth along the steep cliff.

„The Quarry“ by Albrecht Dürer, probably painted in 1495.

Despite never really completely mastering the geometrical rules necessary to create a perfect perspective in a painting, Dürer nevertheless popularized this new technique in Europe. Soon, many other artists followed and began painting realistic landscapes, even studying rocks in order to correctly depict them in their art.

References:

  • ROSENBERG, G.D. (2009): The measure of man and landscape in the Renaissance and Scientific Revolution. In Rosenberg, G.D., ed., The Revolution in Geology from the Renaissance to the Enlightenment: Geological Society of America Memoir 203: 13-40

Pyroclastic Flows of the Athesian Volcanic Group

May 8, 1902, began as a sunny day in Martinique, an island in the Caribbean, with only a column of steam rising above Mount Pelée. When the volcano suddenly exploded.

The first rescuers arrived on the site twelve days after the eruption, accompanied by British, French and American geologists. In the city of St. Pierre, almost all of the buildings had been destroyed and an estimated 20.000-40.000 people killed.

» I looked back and the whole side of the mountain, facing towards the town, seemed to open and topple down on the screaming people. I was burned by stones and ashes …, but I got to the cave «

Havivra Da Ifrile, a girl who survived the destruction of St. Pierre hiding inside a cave near the shore.
Photographs of the city of St. Pierre before and after the eruption of Mount Pelée, the volcano is seen in the background (from LACROIX 1904, NHM Paris).

Geologist Edmund Hovey of the American Museum of Natural History, among the first to arrive to the destroyed city, noted that “In many places the limit [of the devastation] passes single trees, one side is dark and burned, the other green as if an eruption never happened.” A lava flow or landslide could not explain the burned trees nor could it explain the sharp boundary between the destroyed and untouched areas.

Two months later, geologists Tempest Anderson and John S. Flett of the Royal Society of London survived a smaller eruption of Mount Pelée.

» The cloud had a spherical form and resembled rounded protuberances amplifying and doubling with terrifying energy. They extended to the sea, in our direction, boiling and changing shape at every moment. It didn’t spread laterally. It didn’t rise up in the atmosphere, but it descended on the sea as a turbulent mass… «

Sequence showing a pyroclastic flow photographed December 1902 by French volcanologist Alfred Lacroix (from LACROIX 1904).
Alfred Lacroix.

For the very first time geologists observed a deadly nueé ardente – an incandescent cloud or glowing avalanche as the phenomenon was first named by French volcanologist Alfred Lacroix in 1904. A nueé ardente, in modern literature referred to as a pyroclastic density current, is a mixture of volcanic material and hot gases. Because its density is greater than air, it sinks downward, flowing like an avalanche along the slopes of a volcano. Pyroclastic flows can originate from the collapse of the eruption column, from a lateral blast or from the partial collapse of a volcano.

Researchers were able to estimate temperatures inside the pyroclastic flow that destroyed St. Pierre based on the observation that bottles melted (glass melts at ~700°C), but copper tubes were not deformed (copper melts at 1.100°C). The geologists, therefore, concluded that temperatures of a pyroclastic flows can range between 700 to 1.000°C. The high temperatures inside a pyroclastic flow also explain why so many people perished in St. Pierre. The heat was so intense that it instantly burnt the outer layers of skin and flesh. As the flesh shrinks due to the loss of water, the inner organs were squeezed out from their cavities. Even those not hit directly by the pyroclastic flow weren’t spared. Inhaling the still 300°C hot gases, their lungs quickly filled with liquid, drowning them.

The photo shows a 200 million-year-old ignimbrite – a name used for lithified deposits of a pyroclastic flow and derived from the Latin word for fire – of the Athesian Volcanic Group. Some of the larger clasts in the photo show an outer rim, indicating that the temperature inside the pyroclastic flow was high enough to alter the mineralogical composition of the rock. The larger rocks are embedded into a matrix of volcanic ash. Pyroclastic flows – a mixture of rocks, overheated gases and vapour – are able to transport even large boulders at a speed of 160km/h. As a result, the impacting mass destroys everything in its path, as happened to the town of St. Pierre.

An exceptional fossil discovered in 1931 in Athesian Volcanic Group deposits – “Tridentinosaurus antiquus by GB Piaz” – The skeletal remains are surrounded by a carbonaceous patina of soft parts, making it the oldest body fossil found in the Southern Alps. It is suggested by some authors, based on the preservation of the fossil, that the animal was killed during a volcanic eruption by a pyroclastic surge.

References: