570mya) is a 4000 my long period known as the Precambrian, this includes approximately 90% of geological time of which we know very little about as pre-Cambrian rocks are poorly exposed, many have been eroded or metamorphosed and fossils are seldom found. The Precambrian has been divided into 3 Eons: 1.Hadean (4600-3800 mya of which there is no rock record) 2.Archean 3800-2500 mya) 3.Proterozoic 2500-570 mya. The present atmosphere is greatly depleted in Ne, Xe and Kr which are inert gases that should
into the mantel below the crust and melts. Hot magma from the mantle breaks through a weak spot in the crust. As the Ziehm 2 magma shoots out of the crust, the cooling magma called lava becomes hard. After significant time, the hard lava forms a volcanic mountain. Volcanoes can form in many different sizes and shapes. They can look like a cone, have steep looking flanks, or look as if they were long cracks in the earth’s crust. (Plummer et al., 2000). If the mountain is very tall, then there is a
landforms in arid regions. They consist of flat or sloping surfaces where stones are closely packed angular or rounded, and generally exhibit low relief (Mabbutt, 1977). Pavements tend to form on both alluvial fan toposequences and on weathering volcanic flow fields in arid regions. Soils are often found under desert pavements and they play an important role in the evolution of pavements (McFadden et. al., 1987). In the past there have been several theories as to the formation pavements and soil
It is Oregon?s only national park. It is the deepest lake in the United States and is the seventh deepest in the world. Crater Lake has an average diameter of 5.3 miles in length and is approximately 1,932 feet deep. Crater Lake is a result of a volcanic explosion that happened about 7,000 years ago. A long time ago, the pacific oceanic plate was gradually moving under the pacific continental plate in the process of plate tectonics. The pressure shaped the land to move upward and create a line of
Mars is the fourth planet from the sun at about 228 million-km (141 million miles) and the last terrestrial planet from the sun. The next five planets in order from the sun are gaseous. Mars follows closely behind Earth but is comparatively smaller, with about half the diameter of Earth and about one-tenth of Earth’s mass. Thus the force of gravity on Mars is about one-third of that on Earth. Though it is much smaller, Mars does have the same surface land area as Earth. Other than Earth
cause of volcanic activity. These plates are always in motion. They move very slowly; however, at times, they bump into each other. These movements put a lot of pressure on the surface rock. Volcanoes obtain their energy from such movement and pressure. Volcanoes form at the boundaries of these plates where two types of movement occur: two plates will collide with each other, or the plates will move apart from each other. Some of these plate layers are cooled and are made up of rigid rocks. The effects
Science of Volcanic Activity Prediction Since the dawn of history, volcanoes have been an awe inspiring feature of the earth that has frightened and intrigued mankind. Volcanoes have taken the lives of over 250,000 people in the last three hundred years and changed the lives of millions of others, but up until recently humans have had very little understanding of the volcanic processes that presage an eruption. The advent and implementation of new technologies and scientific methods has allowed
Earthquakes Earthquakes, one of the most destructive natural phenomena, consist of rapid vibrations of rock near the earth's surface. Because of their unpredictable occurrence and enormous capacity of destruction, they have brought fear to mankind since ancient times. A single shock usually lasts no more than a few seconds, but a series of smaller quakes may last for as long as five minutes. The quake felt on the surface is always the result, not the cause of some underground geologic process,
Landslides are the down slope movement of mass of land, rock, soil, or related debris. In most mass movement, water plays a pivotal role by assisting in the decomposition and loosening of rock, lubricating rock and soil surfaces to enhance the beginning of movement, adding weight to an incipient landslide, and imparting a buoyancy to the individual particles, which helps overcome the inertia to move. Landslides can also be triggered from volcanic eruptions and earthquakes, which initiate earth
years have been the cause for concern of scientists calling it a global warming problem. Global warming is a natural process as well as a human assisted process. Solar flares and sunspots along with natural elevation of greenhouse gasses due to volcanic activety are the natural causes for global warming. Dr. Judy Lean, a leading astrophysicist, looked at global warming trends from 1860 to the present day. Her research has found from 1860 to 1970, global warming was largely due to natural sources
and the Cordillera Occidental. On the Caribbean coast is the isolated mountain mass known as the Sierra Nevada de Santa Marta, which includes Colombia's highest point at Pico Cristóbal Colón (5776 m/18,950 ft). The Cordillera Central contains the volcanic peaks of Huila (5750 m/ 18,865 ft) and Tolima (5616 m/ 18,425 ft). About 240 km (about 150 mi) south of the Caribbean, the Cordillera Central descends to marshy jungle. The cordillera peaks are perpetually covered with snow; the timberline in these
Goegraphy The geography of Dominica is quite unique. It is an island fortress unlike any other island in the Caribbean, and is the largest and most mountainous of the Windward Islands. The island was created by volcanic activity, and still today shows signs of active volcanic activity. Its steep mountains prevented colonists from completely taking over and have made the island a prime destination for Eco-tourists. The island contains over 3,000 peaks, the tallest of which are Morne Diablotin
to cool very gradually, forming diamond crystals. When volcanic eruptions occur, magma carries the diamonds up to the surface of the earth. Kimberlite lavas carrying diamonds erupt at anywhere between 10 and 30 km/hour and increase their velocity to several hundred km/hour within the last few kilometers. (Pough, 44) At the surface, this lava cools and turns into Kimberlite rock. That is why diamonds are often found in kimberlite, a volcanic rock, which is often much younger than the diamonds themselves
be seen through the unique culture that exists there today. During these changes the politics of Dominica were altered as different tribes had different ways of ruling just like Spain, France, and Britain did too. Millions of years ago fierce volcanic activity began deep below the sea, in the region known now as the Caribbean. Some of these volcanoes managed to push their way up from the ocean floor to become islands; the tallest of these islands is Dominica. Since then Dominica has seen many
classic dinosaurs died: from volcanic activity or an asteroid impact. Although they result in the same outcome, the volcanic and asteroid hypotheses differ in key elements: the actual event, the environment's stress, and the impact on life. Physical evidence left behind in each scenario supports each possible explanation for the massive extinction responsible for wiping out the dinosaurs. Scientists that support the volcanic activity hypothesis believe the massive volcanic activity lasted approximately
over land and through the air: the ash that fired out of the volcano was blown as far east as Nebraska in a huge, dark cloud of plinian ash. A nuee ardente billowed over the rim of the volcano and spread lava to the south, east and north, forming a volcanic outcrop now called the Bishop Tuff. Today, an expanding resurgent dome in the center of the depression indicates current magmatic activity beneath the caldera, and earthquake swarms in the last 25 years could also be linked to subsurface magma movement
glaciated. (Hoffman, 1998) Deglaciation can occur when volcanic eruptions saturate the atmosphere with carbon dioxide gas and resume the greenhouse effect on climate. Solar radiation is absorbed by greenhouse gases, rewarming the climate. A dramatic expansion of the biosphere occurred. ("Cold") History of "Snowball Earth Hypothesis" A tree toppled during a hurricane. A 700 million year old rock bed was discovered in Appalachia. The rock, diamictite consisted of basalt -size cobbles mixed with
Webster’s dictionary definition, are, “a shaking or trembling of the earth that is volcanic or tectonic in origin.” World Book Encyclopedia reports scientists believe that more than 8,000 earthquakes occur each day without causing damage. A little more than 1,000 each year are strong enough to be felt. Earthquakes occur in the general sense, anywhere on land. Other earthquakes go by different names, such as volcanic eruptions and tsunamis, large tidal wave storms that occur underwater, primarily
Key questions for biologists concern what combination of environmental changes could possibly have had such a devastating effect, the scale and pattern of species loss, and the nature of the recovery. New studies on dating the event, contemporary volcanic activity, and the anatomy of the environmental crisis have changed our perspectives dramatically in the past five years. Evidence on causation is equivocal, with support for either an asteroid impact or mass volcanism, but the latter seems most
Tsunamis are most often generated by earthquake-induced movement of the ocean floor. Landslides, volcanic eruptions, and even meteorites can also generate a tsunami. Areas at greatest risk are less than 25 feet above sea level and within one mile of the shoreline. From an initial tsunami generating source area, waves travel outward in all directions much like the ripples caused by throwing a rock into a pond. As these waves approach coastal areas, the time between successive wave crests varies