Geoarchaeology Studying relationships that have existed between Earth’s processes and humans in the past
what we know, the basics: • The destructive nature of earthquakes and associated natural occurrences, such as landslides and tsunamis, lead people to attempt to make senseand perhaps, predict the occurrences. • Relationships are known to exist between the perceptionsof the events and the actual earthquakes but they have not yielded statistical reliability.
Earthquakes can be understood using a variety of methods, including : • Observations and Perceptions (narrative traditions) • Myths and folklore • Eye-witness reports • Earthquake Instrumentation (tool technology) • Instrumental Observation based upon Wave Theory • Instrumental Observation based upon Sound Vibrations
Observations and Perceptions, transmitted through narratives • Passed along, the information is put to practical use, for example: • today, • Information is used to turn off gas, electrical, water equipment • Information is used to warn people to seek cover • in the past: • Information has been used to report the phenomena and activities • Information has been used to communicate with the spirit world
Japan’s National Earthquake Warning System combines the present with the past! • 3Soft Ltd. “Digital Catfish” is a • portable home earthquake warning system that uses • wireless earthquake warning transmissions relayed to smaller speakers placed around the home ( > $850), • combining an already automated system that reports within 2 minutes of the earthquake’s occurrence.
The name, “Digital Catfish” is based upon a giant mythological catfish that lives in mud beneath the earth. The catfish likes to play pranks and can only be restrained by Kashima, a god who protects the Japanese people from earthquakes. So long as Kashima keeps a mighty rock with magical powers over the catfish, the earth is still. But relaxing his guard, the catfish is able to thrash about,causing earthquakes.
Other Myths Ancient Greece • Poseidon controlled, from his sea domain, the devastating force of earthquakes. The widespread belief was that an agitation of the great sea on which the earth floats produced earthquakes. Later understandings incorporated the idea that movement of air in subterrestrial chambers created the earthquake.
India • Naga, a very large snake, is found in Hinduism and Buddhism, and refers to nature spirits that protect springs, wells, and rivers. The term also applies to elephants. It is believed that eight mighty elephants hold up the land. But when one of them grows weary, its head is lowered and shaken, causing an earthquake.
Medieval Europe Lucifer was believed to be responsible for the destruction caused by earthquakes. The belief continued into Puritan New England.
Modern Folklore • “The Swallowing Earth” • Fancy: “When an earthquake happens, a chasm open up along the fault, and anyone standing over the fault will fall in.”
Fact: Sudden movement along a fault may create a shallow crevice. In effect there is settling and ground deformation that can include fissures into which people, houses, etc. can fall.
“Earthquake Immunity” • Fancy: “People are protected from a large earthquake because their home is often shaken by small earthquakes that ‘let off steam.’” • Fact: Moderate earthquakes release only one thousandth of the energy of a large magnitude earthquake. Moderate earthquakes may actually be precursors of larger earthquakes.
“Astrological Causes” • Fancy: “Mars, Jupiter, and Saturn govern the destructive action of the earth, and along with earth tides, trigger earthquakes.” • Fact: Earth tides are caused by the rotating Earth influenced by the combined gravitational pull of the Moon and Sun. Scientific studies do not reveal statistically meaningful correlations of earthquake occurrence with tidal loading.
Still, seismologists are puzzled by correlations that can be made between geophysical events, historical data and oral traditions. There is an increasing awareness of the possibility to recognize people’s memories of past geological events, in particular memories stored as legends and myths (Piccardi 2005).
Active tectonics and earthquake hazards are well known in the Italian peninsula and the Adriatic region. But , to date the relationship between local structures and earthquake sources has not been well studied. Neither has the connection between actual events and legends. • A strong local earthquake was reported in the historic seismic catalogues dating to AD 493 and described as an “immenso tremore”, and has been correlated to the famous legend of the descent of Archangel Michael of Monte Sant’Angelo.
“ The Gargano (promontory) was shaken by a huge tremor, lightning often flew, and a dark cloud covered the whole summit of the mountain.”
After the earthquake, people interpreted some strange imprints found at the entrance of a sacred cave to be the “footprints” of the Archangel. The legend has proven critical in the Medieval western world, influencing the cultural evolution and spread of Christianity to the whole of Europe. The site became a local sanctuary and pilgrimage site.
Eyewitness Reports • People often report a sound like a train just before they feel a quake, which is the P-wave moving as an acoustic wave in the air. • At Moodus, Conn. subterrranean noises caused the town to be called Machemoodus “place of noises” by the Wangunk Indians. Booms and rumbles like thunder, caused during earthquakes, are the result of coupling between the ground and the atmosphere. In this case the low frequency sound waves are “felt” as faraway as New York and Boston. Puritans blamed the sounds on Satan.
People in buildings perceive the arrival of S-waves as a sudden, powerful jolt, as if a giant has pounded his fist down on the roof. 1957 San Francisco M 5.3, Mercalli VI 1964 Alaska M 8.4, Mercalli VIII 1967 Caracas M 6.3, Mercalli VI
Anomalous electrical measurements and changes in regional geochemistry are reported to occur. • Prior to and during slip along the fault, fluid movement in the fault zone causes measurable changes in the electrical and magnetic field of the fault zone (Madden and Mackie 1996). • Concentrations of radon, helium, hydrogen, mercury, carbon dioxide, and several volatiles have been found generally to be anomalously high along active faults, suggesting the faults to be paths of least resistance for the terrestrial gases to escape into the atmosphere (King 1986).
In very strong earthquakes, the up and down and back and forth motions caused by surface waves can make the ground appear to roll like the surface of the ocean.
Animal behavior • Most anomalous animal behavior reports are anecdotal, lacking quantitative evaluation. • However, animals (and humans) may have developed a sensitivity to earthquake precursory signals through evolutionary processes. • Animals living within seismically active regions are more susceptible to burrow collapse resulting in death. Animals with the ability to detect earthquake precursors (seismic escape response gene) would be naturally selected over animals without the ability (Kirschvink 2000).
Abnormal behavior among fish, birds, and small mammals has been correlated with earthquake activity (Rikitake 1976). • Fish migrations are reported by fishermen, including deep-sea carp or mackerel appearing in large numbers in waters much shallower than their normal habitat. • Catfish in fish tanks respond differently when tapping on the tank is coupled with an earthquake (Hatai and Abe 1932).
Earthquake weather • The origins began with ancient Greeks who believed earthquakes occur during hot and dry weather. • Earthquakes occur in subsurface strata, miles below, and can happen anytime, but strange correlations have been made to certain cloud formations.
For scientists, what is next? • There is a need in diverse fields such as geophysics, geochemistry, and animal behavior (human behavior) to define correlations between natural phenomena and earthquakes. Is it (has it been) possible to arrive at earthquake prediction? • The observations of anomalies associated with earthquakes does not prove that earthquakes can be predicted by the anomalies, but, • recent discoveries of correlations between geochemical anomalies (Poitrasson et al 1999) and earthquakes, and electrical measurements (Fraser-Smith et al 1990) suggest a strong potential for earthquake prediction capability.
Earthquake studies increase our understanding of earthquake source mechanisms, structural complexities of fault zones, and earthquake recurrences. • Understanding how, where, and when earthquakes occur, and the instrumentation (tool technology) that can be used to measure may lead to short term earthquake prediction capabilities. • Understanding the human response to earthquakes is necessary to understand 150,000 years of human adaptation and survival.
Early Earthquake Instruments: • AD 136 Chinese spherical copper instrument, 8 feet diameter, • Eight dragon heads on outside, each with a ball in its mouth. Underneath are eight frogs placed to receive the ball if it should be dropped. • When an earthquake occurs, the dragon drops the ball and the frog which receives it vibrates. • Thus, the direction of the earthquake could be determined.
Instrumental Observation based upon Wave Theory: • The wave theory of the propagation of earthquakes was founded on analogies to sound waves and to water waves. • Sound waves as seismic waves ( “earth waves”) begin as a single shock motion or in successory motions. • Water waves model the transversal waves or undulations at the surface of the earth. • Different materials contained in ground soils determine the propagation speed and many refractions, overlayers and reflexions of the wave motions may occur. All are subject to the same basic laws of mechanics that apply to solid and elastic and fluid bodies.
Instrumental Observation based upon Sound Vibrations: • Aristotle was aware that sound emerges when air is compressed and extended in the process. • Experimental investigations of the visible phenomena of vibrations of fluid and solid bodies manifest themselves most visibly in the form of waves.
Case Study: New Madrid Earthquakes 1811-1812 • The earthquakes were centered in New Madrid, Ill. , where the Ohio and Missouri rivers meet the Mississippi. The occurrence was in an area normally devoid of tectonic activity, including earthquakes. • Occurring in late 1811-mid 1812, the events were one of the most dramatic natural disasters to strike the North American continent. • The quake was a signal for Tecumseh, who organized the Iroquois Confederacy around his prophesy of the events. • Eliza Bryan’s (1780-1866) eyewitness account was correlated to other accounts of the phenomena. She relates her experiences in 1816 to the Methodist evangelist Lorenzo Dow. 31 years old at the time of the earthquakes, she was living with her mother in a boarding house at New Madrid.
“ On the 16 December, 1811, about two o’clock, A.M. we were visited by a violent shock of an earthquake, accompanied by a very awful noise resembling loud but distant thunder, but more hoarse and vibrating, which was followed in a few minutes by the complete saturation of the atmosphere, with sulphurious vapor, causing total darkness. The screams of the affrightened inhabitants running to and fro, not knowing where to go, or what to do – the cries of fowls and beasts of every species – the cracking of trees falling, and the roaring of the Mississippi – the current of which was retrograde for a few minutes, owing as is supposed to an irruption in its bed – formed a scene truly horrible.” • “...From this time until the 7th of February the earth was in continual agitation, visibly waving as a gentle sea. On that day there was another shock, nearly as hard as the preceding ones…”
Modified Mercalli Earthquake Intensity Scale • Magnitude Effects observed I not felt except by a very few under special conditions II felt only by few, upper floors, swinging objects III felt noticeably indoors, upper floors; cars rock slightly; slight vibration IV awakened at night; dishes, windows doors disturbed; walls crack V broken dishes; objects overturned; pendulum clocks stop VI frightened people; heavy furniture moved; fallen plaster VII difficult to stand; chimneys broken; noticed by people driving cars VIII considerable damage in buildings; fall of chimneys, columns, walls IX general panic; damage considerable in specially designed structures X wooden structures destroyed; rails bent XI few masonry structures left standing; bridges destroyed; rails bent XII damage total; lines of sight and level distorted; objects thrown in air
Authorized as a National Park in 1926, the cave is the longest recorded cave system in the world. Mammoth Cave was designated as a UNESCO World Heritage Site in 1981, and as an International Biosphere Reserve in 1990. The human and natural resources are protected by national and international law.
At least 10 miles of the cave are known to have been explored by people 4,000 years ago. Archaeological evidence indicates that early dwellers collected crystals and other salts found in the cave. Some 2,000 years ago, prehistoric use of the cave is suggested to have ceased.
New Madrid earthquake 1812, at Mammoth Cave… • “One of my guides informed me, he was at the Second Hoppers, in 1812, with several workmen, when those heavy shocks came on, which were so severely felt in this country. He said about five minutes before the shock, a heavy rumbling noise was heard coming out of the Cave like a mighty wind; that when that ceased, the rocks cracked, and all appeared to be going in a moment to final destruction.”Natum Ward, 1916
The scenic river valleys of the Green River in the hilly country of south central Kentucky.
Surface clues to the existence of caves Karst topography evidencing progressive erosion of sandstone
Shale, conglomeratic beds formed by ancient river system draining west and south