Volcanoes and Earthquakes Based on Discover Gods Creation

Volcanoes and Earthquakes Based on Discover God’s Creation, chapter 4 -1 & 4 -2 By Rebecca Fraker

A few notes This is a large slide show. It would be better to show it in several parts. This slide show includes animations, video clips, and links to websites. Be careful where you click! If the pointer is on a link, your computer will try to take you to the website.

Part 1: Volcanoes • Volcanoes are formed when magma, the melted rock of Earth’s mantle, pushes up through the crust onto the surface. • Volcanoes form on both land in the ocean.

Parts of a volcano Pipe or tube

Parts of a volcano • The vent of a volcano is an opening in Earth’s crust. • From the vent, a tube or pipe serves as a pathway from the mantle to the crust and allows magma to move up and out of the vent.

Parts of a volcano • Lava is magma that reaches the surface. Lava can be thin and almost watery or thick like cookie dough.

Lava & Magma • As lava cools it crystallizes to form rock. • When it cools quickly, it has a smooth texture such as obsidian. • When it cools slowly the rocks are coarser. • Sometimes gasses create “foamy” lava that cools into rocks called pumice and scoria. obsidian granite scoria pumice

Volcanoes • Volcanoes usually form near the boundaries of Earth’s plates. • The Ring of Fire is a region of heavy volcanic activity that surrounds the Pacific Ocean.

Eruptions • Volcanoes also differ in the way they erupt. • In some volcanoes the lava flows out of cracks called fissures. These eruptions do not build mountains but form broad, spreading layers of lava. • Other volcanoes build mountains as they erupt. When lava flows out of the vent and cools, a bowl-shaped crater often forms around the vent. • As new material flows over the top, a cone builds up.

Kinds of Volcanoes • Three kind of volcanoes form mountains: – Shield volcanoes – Cinder cones – Composite volcanoes

Shield Volcanoes • Shield volcanoes are the largest type of volcanoes volcano. • They are broad with gently sloping sides. • They do not have violent eruptions; lava flows out slowly. • The Mauna Loa volcano, perhaps the largest active volcano on Earth, is a shield volcano.

Examples of shield volcanoes: Mauna Loa Volcano in Hawaii

Cinder Cones • Cinder cones are the smallest type of volcano, cones usually less than 1000 feet high. • They form when pieces of lava blow out of a volcano’s vent. • Unlike shield volcanoes, cinder cones have very steep sides. • In 1943, Paricutin, a volcano in Mexico, erupted. • In the first day, a cone of over 130 feet high formed, and within five days it was over 300 feet high. Two years later, this volcano was more than 1300 feet high.

Examples of Cinder cones Paricutin in Mexico

Composite Volcanoes • Mount St. Helens in the United States is a Helens composite volcano • These volcanoes have alternating layers of lava and ash. • Lava quietly flows out for a time. • When the lava stops flowing, a plug forms in the vent. In this condition, the volcano may stay inactive for many years.

Composite volcanoes • When a composite volcano again becomes active, there is no place for magma and steam to go. • As pressure within the volcano builds, there is an explosion that blows out the plugged vent. • Such eruptions release tremendous power. • The eruption of Mount St. Helens blew away most of the mountain’s north side.

Examples of composite volcanoes Mount St. Helens before eruption And afterwards, in 1982

Some products of volcanic eruptions Steam and gases lava Fine ash rocks

Famous eruptions • Volcanic eruptions have had a dramatic impact on the Earth’s surface and on the lives of people and cultures. • Following are accounts and pictures of some of the more famous eruptions.

Mount Krakatoa • So much pumice was released onto the ocean’s surface from the eruption of Krakatoa in 1883 that sailors were able to walk 2 miles from their ship to the shore on top of the floating pumice! Krakatoa before and after

Krakatoa • A volcanic island of Indonesia between Sumatra and Java. A momentous volcanic explosion on Aug. 23, 1883, blew up most of the island altered the configuration of the strait; it caused a tsunami that killed more than 36, 000 people along the nearby coasts of Java and Sumatra. • The explosion is classed as one of the largest volcanic eruptions in modern times; so great was the outpouring of ashes and lava that new islands were formed, and debris was scattered across the Indian Ocean as far as Madagascar. Since then there have been several lesser eruptions.

Mt. Vesuvius • POMPEII, MT. VESUVIUS, ITALY In 79 AD, Mt. Vesuvius erupted an enormous volume of pumice and ash. This material flowed very quickly down the side of the volcano as hot ash flows. The ash flows covered the Roman city of Pompeii in a few hours. Many people were trapped by the hot ash. Almost the entire population of the city was killed.

Pompeii and Mt. Vesuvius • Pompeii is undoubtedly one of the world's best known archaeological sites. Its fame comes from its dramatic destruction and extraordinary preservation as a result of an eruption of Mount Vesuvius. • On February 5, A. D. 62, Pompeii was at the epicenter of a severe earthquake that caused considerable structural damage to buildings and the infrastructure of the city. It is clear that the process of repair and redevelopment was slow and extensive.

Pompeii • On August 20, A. D. 79, Pompeii was rocked by more earth tremors. Springs in the area dried up. • The ancient Pompeiians did not recognize that these were signs of the imminent eruption of Vesuvius. Therefore when the volcano went off between noon and 1 pm on August 24, it caught everyone by surprise. • According to Pliny the Younger, a 12 -mile high cloud of ash and rock was thrown into the air, blocking out the sun.

• By chance, the wind was blowing from the northwest, so when the volcanic matter began to fall, it was blown in the direction of Pompeii, Herculaneum and other sites to the southeast. • The eruption produced total darkness, as well as electrical discharges from atmospheric disturbances. • Ash, pumice, and rock fell, initially with a low density. This piled up in streets, on rooftops, and fell in through every open space such as windows. • Some roofs collapsed under its weight and falling debris may also have caused injury.

• This phase of the eruption continued for the rest of the day. People wandered around in darkness, pushing their way through pumice and debris, which was piling up. Some may have tried to escape, while others decided to wait it out. Surely no one had experienced such a catastrophe before so they did not know what to expect from it. • Shortly after midnight, ground surges of magma and volcanic mud began as well as pyroclastic surges, avalanches of noxious gases and ash rushing from the cone of Vesuvius with terrific force at over 100 kilometers an hour Pompeii

• Herculaneum, which was situated at the base of Vesuvius, was hit with a surge and entombed in volcanic mud. Several pyroclastic surges roared toward Pompeii but were stopped from doing too much damage by the northern city wall right behind our city block. At about 7: 30 am, enough pumice stones and debris had piled up that a pyroclastic surge finally rolled up over the top of the city wall, shearing off any buildings that were not already buried by volcanic matter. All people still present in the city died instantly. • Thousands of people died within the city during the eruption. Many more were probably killed in the surrounding landscape as they tried to flee, but little archaeological work has been done on Pompeii's hinterland. A powdery deposit followed the most destructive surge and when the eruption finally ceased late on August 25, only the largest structures in the city such as the Amphitheater and the Grand Palaestra were probably identifiable.

• Pompeii and Herculaneum were to remain buried for around 1, 700 years. Survivors of the eruption must have decided that rebuilding on the site was out of the question, but some researchers claim that there were signs that for a time people lived in the ruins, and a fishing community probably existed at the mouth of the nearby river Sarno. • During the later Roman period, and into the Middle Ages, Pompeii was forgotten. In March 1748, a surveying engineer, was sent by King Charles III of Spain with a mission to supply the Spanish court with ancient statues and other treasures. He learned that at the place called La Cività (what the people of the country called this area) objects of antiquity had been found. The excavations at Pompeii have continued ever since.

Mosaics, pottery, and casts of people buried in the Mt. Vesuvius eruption about 80 years after Jesus’ crucifiction.

• CRATER LAKE, OREGON Crater Lake erupted about 7770 years ago. It was a gigantic eruption of ash flows. So much material erupted that the top of this volcano collapsed. • This formed a great hole where the top of the volcano had been. The hole was gradually filled with water from rainfall and melting snow. A new eruption in the middle of the lake formed a tiny cinder cone volcano, now called Wizard Island.

PARICUTIN, MEXICO A cinder cone grew to a height of more than 1500 feet. It first began in a cornfield in 1943. The volcano grew and erupted a lot of lava, eventually covering more than 10 square miles. It frightened farmers, but enough warning was given for most of the local population to escape without harm.

Mt. Pelée on Martinique • The island of Martinique lies in the Caribbean Archipelago between the Atlantic Ocean and the Caribbean Sea. Mt. Pelée, located on the northern side of the island, proved to be the deadliest volcano of the 20 th century.

Mt. Pelée • Three days before the eruption, the rim of the volcano crater collapsed, sending scalding water down the nearby River Blanche. Collecting debris along the way, the mudflow buried everything in its path before reaching the sea. • The impact created a nearly ten-foot-high (three-meterhigh) tsunami, flooding the low-lying areas around St. Pierre.

Mt. Pelée • Mt. Pelée erupted at 7: 50 a. m. on May 8, 1902. A giant black plume darkened the sky, while a pyroclastic flow—a superheated cloud of hot ash, toxic gases, and magma fragments—raced down the volcano's sides at hurricaneforce speeds. • Within minutes, the city of St. Pierre had been destroyed, its 30, 000 inhabitants dead.

Mt. Pelée • One of only two survivors, 25 -year-old Louis-Auguste Cyparis was in jail when the volcano erupted the morning of May 8, 1902. Cyparis had been moved to solitary confinement in an underground cell. The thickness of the walls and absence of windows sheltered him from the most deadly effects of the eruption, but Cyparis was severely burned by hot air and ash. In great pain, he managed to survive trapped in the cell for four days until scientists exploring the ruins rescued him.

Some resources http: //volcano. und. nodak. edu/vwdocs/current_volcs/curre nt. html Information on currently erupting volcanoes around the world, with links to each site. http: //www. geo. mtu. edu/volcanoes/ Michigan Technological University - volcano sites from around the world. http: //vulcan. wr. usgs. gov/home. html The US Geological Survey Cascades Volcano Observatory. Excellent information on US volcanoes, as well as plate tectonics and geologic hazards.

Part 2: Earthquakes and Tsunamis • Earthquakes are shock waves resulting from movements in Earth’s crust. They have occurred throughout the history of the world. • Scientists estimate that worldwide, over 800, 000 earthquakes occur each year. • Most earthquakes are too small to be felt, but they can be detected by special equipment.

Where do earthquakes take place? • Earthquakes often happen near boundaries of plates and at faults, or cracks in the plates. • As the plates move, pressure builds up in the rocks along the fault. • If movement stops, the energy remains stored in the rocks. • If movement continues, the rocks can no longer hold their position and suddenly they slip past each other. • To illustrate this, try bending a small branch you have taken from a bush or tree. It will bend so long, and then snap.

Faults • Only one side of a fault moves. The moving plate can either push up, slip down, or move horizontally. • There are three kinds of faults: – Normal faults – Thrust faults – Strike-slip faults (transform faults)

Normal Faults • The moving plate slips below the stationary plate. • The fault that runs through the Rift Valley of Africa is an example of a normal fault.

Thrust Faults • The moving plate moves up and over the stationary plate. Chief Mountain in Montana is an example of a thrust fault.

Thrust faults

Strike-Slip Faults • The moving plate slides past the stationary plate. The San Andreas fault in California is a strike-slip fault.

Strike-Slip faults

Focus and Epicenter • The point where the actual slip happens is the focus of the earthquake. It is usually focus deep within the earth. • Energy waves travel out in all directions from the focus.

Focus and Epicenter • The epicenter of an earthquake is the point on the surface of the ground directly above the focus. • If you were standing at this point, you would be the first to feel the earthquake.

Earthquakes Today • Today we have more than 4, 000 seismograph stations in the world that record 12, 000 to 14, 000 earthquakes per year—that’s about 35 a day!

Some earthquakes • Here are some earthquakes that have caused great loss of life and great damage: – China, 1920, 7. 6, 180, 000 – China, 1976, 7. 6, 250, 000 – Japan, 1923, 8. 3, 140, 000 – Peru, 1970, 7. 7, 70, 000 – Mexico, 1985, 8. 1, 10, 000 – Afghanistan, 1998, 6. 9, 5, 000

San Francisco Earthquake • "San Francisco and Oakland are becoming as Sodom and Gomorrah, and the Lord will visit them. Not far hence they will suffer under His judgments. "--Ms 30, 1903. Ellen G. White

Other quotes: • On April 16, 1906, two days before the San Francisco earthquake, Mrs. White said that, • “While at Loma Linda, California, April 16, 1906, there passed before me a most wonderful representation. During a vision of the night, I stood on an eminence, from which I could see houses shaken like a reed in the wind. Buildings, great and small, were falling to the ground. Pleasure resorts, theaters, hotels, and the homes of the wealthy were shaken and shattered. Many lives were blotted out of existence, and the air was filled with the shrieks of the injured and the terrified. The destroying angels of God were at work. One touch, and buildings, so thoroughly constructed that men regarded them as secure against every danger, quickly became heaps of rubbish. There was no assurance of safety in any place. I did not feel in any special peril, but the awfulness of the scenes that passed before me I cannot find words to describe. It seemed that the forbearance of God was exhausted and that the Judgment day had come. “ (Testimonies, Vol. 9, pp. 92 -93) • Two days later, on April 18, 1906, a devastating earthquake struck San Francisco

Where are the faults in the United States? San Andreas Fault, California New Madrid Fault, Mississippi River Valley

Where are faults in the United States?

California

Earthquake fault lines • Earthquakes in the United States have happened in Hawaii, Alaska, California, and the Mississippi River Valley. Alaska is the most earthquake-prone state and one of the most seismically active regions in the world. Alaska experiences a magnitude 7 earthquake almost every year, and a magnitude 8 or greater earthquake on average every 14 years.

Earthquake Facts • • • The largest recorded earthquake in the United States was a magnitude 9. 2 that struck Prince William Sound, Alaska on Good Friday, March 28, 1964 UTC. The largest recorded earthquake in the world was a magnitude 9. 5 (Mw) in Chile on May 22, 1960 The earliest reported earthquake in California was felt in 1769 by the exploring expedition of Gaspar de Portola while the group was camping about 48 kilometers (30 miles) southeast of Los Angeles.

Earthquake Facts • • It is thought that more damage was done by the resulting fire after the 1906 San Francisco earthquake than by the earthquake itself. Each year the southern California area has about 10, 000 earthquakes. Most of them are so small that they are not felt. Only several hundred are greater than magnitude 3. 0, and only about 15 -20 are greater than magnitude 4. 0. If there is a large earthquake, however, the aftershock sequence will produce many more earthquakes of all magnitudes for many months.

Even a pool can be a seismometer • A seiche (pronounced SAYSH) is what happens in the swimming pools of Californians during and after an earthquake. It is "an internal wave oscillating in a body of water" or, in other words, it is the sloshing of the water in your swimming pool, or any body of water, caused by the ground shaking in an earthquake. • It may continue for a few moments or hours, long after the generating force is gone. A seiche can also be caused by wind or tides.

Earthquake facts 1. • • The magnitude of an earthquake is a measured value of the earthquake size. The magnitude is the same no matter where you are, or how strong or weak the shaking was in various locations. The intensity of an earthquake is a measure of the shaking created by the earthquake, and this value does vary with location. From 1975 -1995 there were only four states that did not have any earthquakes. They were: Florida, Iowa, North Dakota, and Wisconsin. The swimming pool at the University of Arizona in Tucson lost water from sloshing (seiche) caused by the 1985 M 8. 1 Michoacan, Mexico earthquake 2000 km (1240 miles) away.

New Madrid Fault Earthquakes occur in the central portion of the United States too! Some very powerful earthquakes occurred along the New Madrid fault in the Mississippi Valley in 1811 -1812. The effects of shaking from these magnitude 8+ earthquakes caused church bells to ring in Boston, Massachusetts, nearly 1600 km (1000 miles) away.

China Earthquake Facts 1. The world's deadliest recorded earthquake occurred in 1556 in central China. It struck a region where most people lived in caves carved from soft rock. These dwellings collapsed during the earthquake, killing an estimated 830, 000 people. In 1976 another deadly earthquake struck in Tangshan, China, where more than 250, 000 people were killed. 2. The earliest recorded evidence of an earthquake has been traced back to 1831 BC in the Shandong province of China, but there is a fairly complete record starting in 780 BC during the Zhou Dynasty in China.

Earthquakes can cause tsunamis • If an earthquake occurs under the ocean, a large wave called a tsunami may form. • Tsunamis can travel at nearly 400 mph across the ocean. • Some tsunamis cause waves several hundred feet high. When they hit land, they are extremely destructive.

Tsunamis • In the last few years, several tsunamis have caused hundreds of thousands of deaths as well as massive property destruction worldwide.

Earthquake & tsunami Summer 2006 • Off the island of Java, Indonesia, an earthquake rumbled under the ocean on July 17, 2006. The motion triggered a tsunami that struck the island about an hour later. At 5: 07 pm local time on July 17 a 10 foot high tsunami hit the Indonesian island of Java. • According to news reports, the area most devastated was the area around Pangandaran, located about 25 miles (40 kilometers) west of the city of Cilacap. This area is a fishing community and resort area. Larger structures withstood the tsunami, but many smaller buildings and homes were washed away. • The death toll has now reached 525 people with 273 people still missing. More than 35, 000 people were displaced by the wave.

……summer 2006 • According to the U. S. Geological Survey, the tsunami was caused by a 7. 7 magnitude earthquake with an epicenter about 155 miles off the coast of the island. The earthquake occurred in a shallow part of the boundary between the Australia Plate and the Sunda Plate. The two tectonic plates meet offshore of the island of Java is located to the north of the Java trench, the surface expression of a subduction zone.

(summer) July 19, 2006 tsunami

December 2004 Tsunami • The video clips on this website were taken by ordinary people with ordinary video cameras. These people were trapped in the tsunami. • http: //www. asiantsunamivideos. com/

December 2004 Tsunami (article by Wikipedia) The 2004 Indian Ocean earthquake, known by the scientific community as the Sumatra-Andaman earthquake, was an undersea earthquake that occurred at 00: 58: 53 UTC (07: 58: 53 local time) December 26, 2004, with an epicentre off the west coast of Sumatra, Indonesia. The earthquake triggered a series of devastating tsunamis that spread throughout the Indian Ocean, killing large numbers of people and inundating coastal communities across South and Southeast Asia, including parts of Indonesia, Sri Lanka, India, and Thailand. Although initial estimates have put the worldwide death toll at over 275, 000 with thousands of others missing, recent analysis compiled lists a total of 229, 866 persons lost, including 186, 983 dead and 42, 883 missing. The figure excludes 400 to 600 people who are believed to have perished in Myanmar which is more than that government's official figure of only 61 dead.

(article from Wikipedia) • This catastrophe is one of the deadliest disasters in modern history. The disaster is known in Asia and in the international media as the Asian Tsunami. • The magnitude of the earthquake was originally recorded as 9. 0 on the Richter scale, but has been upgraded to between 9. 1 and 9. 3. At this magnitude, it is the second largest earthquake ever recorded on a seismograph. This earthquake was also reported to be the longest duration of faulting ever observed, lasting between 500 and 600 seconds, and it was large enough that it caused the entire planet to vibrate at least half an inch, or over a centimetre. It also triggered earthquakes in other locations as far away as Alaska. • The earthquake originated in the Indian Ocean just north of Simeulue island, off the western coast of northern Sumatra. The resulting tsunami devastated the shores of Indonesia, Sri Lanka, India, Thailand other countries with waves up to 30 m (100 ft). It caused serious damage and deaths as far as the east coast of Africa, with the furthest recorded death due to the tsunami occurring at Port Elizabeth in South Africa(5, 000 mi) away from the epicentre.

This is a very short video clip. It was taken by a tourist on the 3 rd floor of a hotel.

This video clip from the 2004 tsunami shows the earthquake first, which then causes the tsunami to start. About 3 minutes.

December 2004 Tsunami

Seismographs • A seismograph records the shock waves created by earthquakes. • A seismograph consists of a rotating drum that moves a strip of paper at a constant speed. Resting on top of the paper is a pen that draws a straight line as the paper moves beneath it. • Vibrations caused by earthquakes waves make the pen scribble on the paper

Seismograph Chinese earthquake detector

Three kinds of shock waves: • An earthquake produces three kinds of shock waves: – Primary waves – Secondary waves – Surface waves They are also known as “P-waves”, “S-Waves”, and “L-Waves”.

Primary Waves • Primary Waves (P-Waves) are like those made by pushing a Slinky in a forward direction. They are created by the backand-forth movements of rock that makes up the crust. • Primary waves travel more than 28, 000 mph and are the first to reach the seismograph. • But although P-waves travel fast, they DO NOT cause damage on Earth’s surface.

Primary Waves

Secondary Waves • Secondary Waves (S-Waves) are created by the up-and-down movements of underground rock. • S-Waves are the second earthquake wave to reach the seismograph and also DO NOT cause surface damage.

Surface Waves • Surface waves (L-Waves) are created on the surface of the earth. • They move more slowly than the other type of waves and are created by the movement of the S-waves. • L-waves are similar to the ripples created when you throw a large rock into a pond of lake. • They make earth’s crust move and are the waves that cause earthquake damage.

Surface Waves

Key Concepts: • Body waves travel through the earth • there are two types of body waves – P-waves (Primary waves) and S-waves (Secondary waves) are body waves • P-waves arrive first and are small • S-waves arrive second are bigger • Surface waves arrive last, and they are the biggest – The particles do not travel with the wave, they return to their original position • P-waves move particles parallel to the direction of wave propagation • S-waves move particles perpendicular to the direction of wave propagation • P-waves can travel through solids and liquids • S-waves can only travel through solids

Charles Richter • In the 1920 s when scientists began to study earthquakes, Charles Richter, a physics student, was given the job of studying the readings of seismographs to determine the epicenters of earthquakes. • He had to describe the size and strength of each earthquake. By 1935, he developed a better method of measuring earthquakes. • He used the seismograph readings and compared the largest surface waves of each earthquake. He assigned each one a number from 1 to 10. Each step was ten times the strength of the step before. • So a magnitude 3 earthquake would be 1 x 10, or 100 times a magnitude 1 earthquake.

What is a small earthquake? • Earthquakes measuring 4 or less on the Richter scale are considered small. • Small earthquakes occur more than 700 times a day. • Large earthquakes, those measuring greater than 7 on the Richter scale, occur less frequently. • Usually fewer than 20 large earthquakes happen each year throughout the world.

Predicting Earthquakes • So far, scientists have been able to predict only where most earthquakes will probably occur, not when.

Connections Between Volcanoes and Earthquakes • In 1980, when Mt. St. Helens, a volcano in Washington state, erupted it showed the relationship between earthquakes and volcanoes. Mt. St. Helens is along the Ring of Fire. • From 1975 to 1980, more than 45 earthquakes occurred on or near the mountain. • In the month before the eruption, there were as many as 15 earthquakes happening there each hour. • The earthquakes culminated in a large-magnitude earthquake just as the volcano erupted.

Connections between earthquakes and tsunamis • This animation shows the connection between earthquakes and tsunamis in the December 2004 event. On Sunday 26 December 2004, a Magnitude 9. 0 earthquake occurred off the West Coast of Northern Sumatra in the Indian Ocean. The world’s strongest forty years, it generated a massive tsunami that is known to have claimed around 300, 000 lives. Animation credit: NOAA