Geology 1313 Earthquakes And Volcanoes

ISNS 4359 EARTHQUAKES AND VOLCANOES (E&V) Spring 2005 Steve Bergman, Instructor Lecture 3. History of Volcanology & Seismology: Myths, Legends, Science Curious humans have long marveled at natural processes such as E & V, and speculated about their causes. The inaccessible nature of the Earth's interior has led to wild speculation about its origins. Renaissance writers compared the Earth to a human body with a circulatory system in which blood represented underground rivers. When bodily processes became unsettled, sickness ensued, so when interior rivers and caverns were disturbed, E & V followed. Gas expansion has figured prominently in the explanation of volcanoes because of its association with natural eruptions. Our knowledge of human evolution is intimately linked with volcanic eruptions, as the oldest known fossils occur in volcanic deposits in Africa and Indonesia, eg., the 3.7 million year old (Ma) Australopithecus hominid footprints in volcanic ash at Laetoli, & 1.7 Ma Homo habilis fossils at Olduvi Gorge, both E. Africa. Volcanoes also provided the raw materials for 2.5 Ma stone tools and weapons used by early humans, and 7th century BC pozzolana cement using Greek and Italian ash. Volcanic eruptions may have played a role in the controlled use of fire by 1.5 Ma Homo erectus (burnt clay Chesowanja, Kenya). Volcanic eruptions have inspired worship, myths, & legends. Many primitive people believed volcanoes were inhabited by temperamental demons that could be appeased with human sacrifice (eg., Mayans, Aztecs, Incas, Nicaraguans, Javanese, East Africans). Science-System of Knowledge (patterns of Facts); figuring out how the universe works; search for explanations of natural phenomena based on physical and logical principles; began ~600BC with the Greek Ionian School of Philosophy. Science evolves and advances as new analytical methods are developed and new data are acquired. Scientific theories can never be proved, only falsified. Science is testable and verifiable. Science is distinct from religion, which is based on faith and belief. Scientific Method - Critical process of asking questions about the observable world, devising explanations, and tests of alternatives to eliminate some. Myth-A belief or theory not based on fact or reality, often involving supernatural beings. A Timeline of Relevant Ideas & Developments Scientist Year Hypothesis, Discovery, or Development Thales of Milatus ~580 BC Water caused earthquakes (EQ) (Earth like a ship floating on the sea) Anaximenes ~550 BC Falling rocks in Earth's interior caused EQ Pythagoras of Samos ~520 BC Suggested Earth was a sphere (not flat) with a central fire Anaxagoras ~450 BC Eruptions & EQ caused by great winds of ether inside the Earth Empedocles ~440 BC Greek Corporeal Elements: Air, Fire, Water, Earth; Earth has a molten center Plato ~380 BC Subterranean river of fire, Pyriphlegathon, was the source of lava flows Aristotle ~330 BC EQ & volcanoes were related and caused by internal fire & wind Eratosthenes ~240 BC Calculated 25,000 mi Earth circumference using noon shadows in Syene & Alexandria Seneca 62 AD Combustion of coal, bitumen, Sulfur inside the Earth was a source of eruptions Pliny the Younger 79 AD First detailed recorded observations of Vesuvius eruption (from afar) Chang Heng 132 AD Built Chinese Earthquake watercock, primitive seismometer Avicenna (ibn Sina) ~1000 AD EQ caused mountain upheavals Snorri Godi 1000 AD Basaltic rocks in Iceland resulted from a lava flow Albertus Magnus ~1250 Mountain uplifts caused by EQ and released vapors from interior Agricola (G. Bauer) ~1550 EQ caused by reaction of central fire and water vapors Konrad Gesner ~1560 Columanar basalts precipitated from seawater (Neptunist) Cardan ~1570 Fiery vapors charged with sulfur, nitre, & bitumen caused EQ James Ussher 1650 Calculated earth formation on 23 Oct 4004 BC Isaac Newton 1692 Speculated Earth interior heated by mineral fermentation G.W. von Leibniz 1749 Proposed the earth’s interior was molten, the crust having formed by cooling John Mitchell 1755 Observed Lisbon EQ, first to measure seismic velocity Nicholas Desmarest 1763 Columnar basalts from Clermont, Auvergne were lavas (Plutonist/Vulcanist) Abraham Werner 1790 Neptunist Leader; Ocean source of all rocks-Great Deluge Legend Lord Cavendish 1798 Calculated Earth mass 6.6e21 tons & bulk density 5.5 gm/cc using Newton's Laws John Playfair 1802 First to propose rocks melted at higher temperatures with increasing pressure Charles Lyell 1830 EQ & volcanoes caused by heat escaping from the core Robert Mallet 1851 EQ caused by sudden rupturing of the crust, releasing massive forces; used dynamite to measure elastic waves in surface rocks George B. Airy 1855 Used isostasy to explain thick light crust floating on dense mantle G.-A. Daubre 1866 Suggested Fe-Ni meteorites were similar to Earth's core John Milne 1880 Installed first seismometer in Yokohama, Japan & elsewhere Osmond Fisher 1881 Proposed convection currents within the Earth Bunjiro Kuto 1891 First to propose movement along a fault as the cause, not the effect, of EQ Lord Kelvin 1897 Proposed <100 Ma age of Earth based on heat flow Andrija Mohorovicic 1909 Used seismic waves to recognize discontinuity at base of crust Alfred Wegener 1912 Proposed continental drift theory and Pangea supercontinent Joseph Barrell 1914 Defined Earth lithosphere (strong), asthenosphere (weak) and centrosphere Arthur Holmes 1928 Decompression melting of peridotite caused by mantle convection K. Wadati 1935 Defined dipping subduction zones based on EQ distribution Inge Lehmn 1936 Produced evidence of the existence and nature of the core Warren Carey 1950s Presented Expanding Earth Alternative Hypothesis (rejected) M. Ewing & B. Hazen 1953 Discovered Mid Atlantic Ridge-Great Global Rift Harry Hess, F. Vine, 1960s Proposed modern plate tectonic theory (verified) D. Matthews, T. Wilson, et al. Summary of “scientific” (natural philosophy) ideas

600 BC-500 AD: Ionian School & Classical Antiquity (Thales, Aristotle, Pythagorus, Plato, Aristotle) EQ caused by subsurface water, air, falling rocks Spherical Earth with molten interior Volcanoes caused by interior fires, combustible coal, bitumen, and sulfur Greek 4 Elements: Air, Fire, Water, Earth Vesuvius 79 AD Pliny Chinese attributed EQ to blocking of the subtle essence (qi) 500-1400 AD: Middle Ages (Magnus, Aristotle, Avicenna/ibn Sina) EQ caused by dry vapors from the sun through earth’s intestines, some vapors are poisonous, causing the plague and disease Mountains caused by EQ and inflated by interior winds EQ caused by large sea beast Iceland basalts were once lavas 1400-1800: Early Modern Times (DaVinci, Agricola, Descartes, Steno, Hooke, Darwin, Humboldt, Hutton) Incandescent Earth core as the cause of volcanic heat Solid Earth Model Neptunist (Werner) - basalts and granites precipitated from seawater (later disproved) Plutonist (Mitchell) - igneous rocks crystallized from magma 1800-1900: Crust ‘floats’ on solid mantle; EQ & volcanoes caused by interior heat; rock descriptions. 1900-1950: Radioactive Heat; Moho; Continental Drift; Geosynclines, Lithosphere/Asthenosphere. 1950-present: Mid-Atlantic Ridge; Magnetic Stripes; Plate Tectonics; Hot spots/Mantle Plumes Most organized religions-Natural disasters result from divine wrath. Some Selected Myths & Legends Native people in Kamchatka, Russia believed earthquakes occurred when a giant dog, Kozei, shook freshly fallen snow from his coat. Early Chinese envisioned the Earth riding on the back of a giant ox, and Mongolians a giant frog. Whenever the animal moved, the Earth shook and trembled. Klamath Indian myths Llao, Chief of the Below World, located on Mt. Mazama (Crater Lake, OR) was locked in a mighty battle with Skell, Chief of the Above World, located at Mt. Shasta (CA). Their battle waged for many years while they threw gigantic stones and fire at each other and darkened the sky with ash, and finally ended when Llao fell back into his underground world, leaving a huge collapsed crater which filled with water to form the deepest lake in N America. This caldera is now known to have formed 6,900 years ago and was presumably observed by many Native Americans. Was Plato's (4th Century BC) Lost Continent of Atlantis in the Aegean? Yes The Bronze Age (1628 BC) eruption of Thera, Greece (Santorini, largest in the Mediterranean in the last 10,000 years), (70 km N of Crete) produced a 6 km diameter caldera, destroying the island, and many tsunamis and floods. This eruption probably led to the decline of the Minoan civilization, burying Akrotiri and other cities, and possibly was the origin of the lost continent of Atlantis, and the seeds of many subsequent Hellenic gods and myths. Greek & Roman Mythology Volcanoes are associated with Pluto, Perephone, Vulcan (unruly child of Jupiter and Juno, lived with his forge inside the volcano on the tiny Aeolian island, Volcano), Typhon (first-born to Gaia -Mother Earth and Zeus, was the largest monster with fire flashing from eyes and flaming rocks hurled from his mouth). Virgil described Mt. Etna eruptions as the burning breath of the Titan, Enceladus, as he struggled to free himself from his underground prison. Earthquakes and Volcanic activity were caused by stirrings of the Titans (giants imprisoned within the Earth) and battles with Olympian gods). Zeus eventually hurled Mt. Etna at Typhon and imprisoned him, his stirring causing earthquakes and eruptions. Neptune (aka Poseidon) was the Earthshaker. Jason and the Argonauts returned to Greece with the golden fleece and were assaulted by Talos, a bronze giant who threw stones at them (at Rhodes and Karpathos and the eruption of Thera with its ejected pumice). Greek Hephaistos (son of Hera & Zeus, spouse-Aphrodite) was the Vulcan father of the monster Cacus. Hades of the Greeks and Hell of the Christians represented eruptions, the eternal fire and brimstone of the Earth's interior, as punishment for a sinful life; Mt. Etna was thought to be a gateway to Hell, going there termed "sailing to Sicily." The Scandinavian god Loki was tied to a rock in a cave as punishment for killing his brother. A serpent would drip poison on him, which was collected in a bowl by his sister. When she emptied the bowl, Loki would twist and turn to avoid the poison, causing the Earth to shake. Ancient inhabitants of India believed the Earth was held up by one of seven serpents that caused trembling when the Earth was switched. Others that Earth was held up by four elephants that stood on the back of a giant turtle, in turn on the back of a cobra. The Japanese believe nature centers around Mt. Fuji, with its majestic symmetry. Instead of viewing volcanoes as demonic, they view Mt. Fuji and other volcanoes as collaborating friendly spirits with supernatural powers. The Oni monster is a horned red giant that hurled rocks out of volcanoes. Ancient Japanese believed a giant catfish, Namazu, which was controlled by a god. When the god turned away, Namazu would flop around and cause earthquakes. A catfish was selected because they exhibit unusual behavior prior to earthquakes. Hawaiians offer flowers, candy, fruit, cloth, and gin to Madame Pele, who carried a magic digging stick that opened up craters wherever she dug. When she was angered, she stamps her foot, causing earthquakes and rivers of lavas to destroy those who displeased her, and killing innocent victims. Princess Ruth Keelikoani was carried near the edge of an advancing lava flow in August 1881 where she chanted incantations, scattered red silk scarves and sprinkled brandy on the lavas. The lava stopped short of a nearby village the next day. New Zealand Maori people believe Taranaki (Mt. Egmont) once stood 125 km east between Tongariro and Ruapehu but stormed off, carving the Whanganui River valley in anger, after observing Tongariro seduce Ruapehu, stopping as the sun set to look back at his wife Ruapehu, and continues to do so today. The Phantom canoe story of Lake Rotorua, with its hot springs and steaming pools, dates to 1886, when 13 people paddling a large war canoe were lost during the eruption of Tarawera. Aztecs of Mexico named volcanoes after their gods, such as Popocateptl (Smoking Mountain) and Iztacchiuatl (Sleeping Woman). When Popo was victoriously returning from a war battle, his enemies sent word ahead to Iztac that he had been killed, and the princess died of grief. Popo then built two mountains, on one he placed Iztac, and on the other he stands eternally holding her funeral torch. Common Themes: Immense Power, linked with supernaturally large animals

Volcanoes, Earthquakes, Faults, and Tsunami are well documented in the Bible: Exodus (13, 19, 20) & Deuteronomy (4:11), Description of volcanic eruption on Mt. Sinai (Precambrian granite), although 2000 BC volcanism is known at Jebel Druse, Syria and elsewhere in N Israel. Job (9:5,6), Amos (1:1), & Zechariah (14:5) Hazor in Galilee was partially destroyed by an EQ at 760BC. Amos (9:6), (Joshua 3:14-17; 4:18)…"when the walls came tumbling down," was possibly associated with an earthquake at 1500 BC. Jerico lies on the Dead Sea fault (1-2 cm/yr), which averages one M6.5-7 earthquake every century over the last 3 millennia. Several later EQ (1267, 1906, & 1927) have caused landslides and the River banks to cave in, which temporarily dammed the Jordan River, possibly permitting passage of the Isrealites. Destruction of the cities of Sodom and Gomorrah (Genesis 19:17), two cities near the Dead Sea coast, could have accompanied seismic and volcanic activity, which are known to have occurred at 1900-2400 BC in the region.