Earthquake Mitigation Measures Minimizing or avoiding the risks from earthquakes involves three subject areas. First is the ability to predict their occurrence. While scientists cannot routinely predict earthquakes, this area is of growing interest and may be a key factor in reducing risks in the future. This information is used to address the third area of earthquake risk reduction-mitigation measures. Following a discussion of prediction, assessment, and mitigation, the types and sources of earthquake information are presented. Earthquake Prediction A report on an erroneous prediction of an earthquake in Lima, Peru, states: Earthquake prediction is still in a research and experimental phase.
Megabeasts’ Sudden Death
Taylor Site, Paluxy Riverbed, , Glen Rose, TX The Taylor Site contains several trackways of largely infilled, metatarsal dinosaur footprints once considered human by many creationists, and a trail of deeper, more typical digitigrade dinosaur tracks. Click image for larger view. Photograph C , Glen J. At one time many YECs argued that such tracks supported their belief that all life forms were created only several thousand years ago, dramatically contradicting the conventional geologic time table that humans did not appear on earth until over 60 million years after non-avian dinosaurs became extinct.
However, the “man track” claims have not stood up to close scientific scrutiny, and in recent years have been abandoned even by most creationists.
A flood, which would cause massive amounts of earth movement, is a much better explanation for the unique placement of both of these fossil types.
Until recent years, scientists who believe in creation haven’t had the necessary resources to explore radiometric dating in detail. A 10 gram sample of U Now that has changed, and some important discoveries are being made. When granite rock hardens, it freezes radioactive elements in place. The most common radioactive element in granite is Uranium This element is locked in tiny zircons within the granite. As part of the decay process, helium is produced. While it stays within the zircon for a period of time, being a very small atom, helium escapes the zircon within a few thousand years.
Social Science History: Time line for the history of society, science and social science
How might the Fairlight area have looked million years ago? Introduction Fairlight is a small village located a short distance from the coast between Pett Level half a mile to the north-east and Hastings 4 miles to the south-west. Over the years coastal erosion has consumed much of the village outskirts and several homes have already toppled over the cliff. A recent study revealed the cliffs had retreated over metres in the last century alone.
Until recently Fairlight was unprotected from the sea, but in the early s a project to construct a wave barrier was completed see below-right.
These TTG calc-alkaline rocks represent the principal means of growth of the continental crust throughout the whole of geologic time.
Also, to introduce students to the major time periods in earth’s history, as well as to the role fossils play in helping us understand this history. Context This lesson is based on an online booklet that provides an introduction to the study of earth’s history, published by the USGS. Using careful analogies and written historical records, the authors help students understand the development of the geologic time scale, including how this depended on gathering evidence and making comparisons.
The major time periods in earth’s history are introduced, as well as are fossils and the role they play in helping us understand this history. Students will likely have been introduced to the geologic time scale in earlier grades, so this lesson is structured loosely to enable you to adapt the content to match the levels and needs of your particular students. Prerequisite knowledge for this lesson includes the idea that: Concepts covered in this lesson, including geologic history, age dating, plate tectonics, timelines, and fossils are prerequisite concepts for understanding the theory of evolution, which is another topic taught at this grade level.
One chapter called Fossil Succession, found in the online booklet Fossils, Rocks, and Time , is particularly useful in helping students understand that the basic idea of biological evolution is that the earth’s present-day species developed from earlier, distinctively different species. Benchmarks for Science Literacy, p.
Specifically, it helps students understand that the kinds of animals and plants found as fossils change over time. It discusses how Darwin’s theory gave scientific meaning to the observed succession of once-living species in the record of earth’s history preserved in the rocks.
How Old Is the Earth?
Creationist Geologic Time Scale: Should the scientific community continue to fight rear-guard skirmishes with creationists, or insist that “young-earthers” defend their model in toto? Introduction This manuscript proposes a new approach for science’s battle against the rising influence in America of pseudo-science and the Creationist movement.
The framework of Creationist Bible-based earth history, focusing on Genesis and the Noachian flood, can be assembled into a single geologic time scale Figure 1 , enlarged by addition of many geologic facts, difficult for Creationists to explain. Figure 1 is an abbreviated version of the time scale outlined in the following paragraph which was redrawn and published by the American Scientist.
Silures a Welsh tribe.
Age of the Universe How old is the world? Ancient commentators propose that the world may be simultaneously young and old. Gerald Schroeder One of the most obvious perceived contradictions between Torah and science is the age of the universe. Is it billions of years old, like scientific data, or is it thousands of years, like Biblical data? When we add up the generations of the Bible, we come to plus years. Whereas, data from the Hubble telescope or from the land based telescopes in Hawaii, indicate the age at about 15 billion years.
Let me clarify right at the start. The world may be only some years old. God could have put the fossils in the ground and juggled the light arriving from distant galaxies to make the world appear to be billions of years old.
The Paluxy Dinosaur/”Man Track” Controversy
Early history[ edit ] In Ancient Greece , Aristotle BCE observed that fossils of seashells in rocks resembled those found on beaches — he inferred that the fossils in rocks were formed by living animals, and he reasoned that the positions of land and sea had changed over long periods of time. Leonardo da Vinci — concurred with Aristotle’s interpretation that fossils represented the remains of ancient life. Steno argued that rock layers or strata were laid down in succession, and that each represents a “slice” of time.
He also formulated the law of superposition, which states that any given stratum is probably older than those above it and younger than those below it.
The universe was aging, but time only grabs hold when matter is present.
The Radiometric Dating Game Radiometric dating methods estimate the age of rocks using calculations based on the decay rates of radioactive elements such as uranium, strontium, and potassium. On the surface, radiometric dating methods appear to give powerful support to the statement that life has existed on the earth for hundreds of millions, even billions, of years. We are told that these methods are accurate to a few percent, and that there are many different methods.
We are told that of all the radiometric dates that are measured, only a few percent are anomalous. This gives us the impression that all but a small percentage of the dates computed by radiometric methods agree with the assumed ages of the rocks in which they are found, and that all of these various methods almost always give ages that agree with each other to within a few percentage points. Since there doesn’t seem to be any systematic error that could cause so many methods to agree with each other so often, it seems that there is no other rational conclusion than to accept these dates as accurate.
However, this causes a problem for those who believe based on the Bible that life has only existed on the earth for a few thousand years, since fossils are found in rocks that are dated to be over million years old by radiometric methods, and some fossils are found in rocks that are dated to be billions of years old. If these dates are correct, this calls the Biblical account of a recent creation of life into question.
After study and discussion of this question, I now believe that the claimed accuracy of radiometric dating methods is a result of a great misunderstanding of the data, and that the various methods hardly ever agree with each other, and often do not agree with the assumed ages of the rocks in which they are found. I believe that there is a great need for this information to be made known, so I am making this article available in the hopes that it will enlighten others who are considering these questions.
Geologic time scale
Those charts showed that a rocky underwater feature known as Six Mile Shoal was actually a continuous underwater ridge stretching miles from northeastern Michigan to southern Ontario. Rather, it would have been a land bridge, with icy lakes on either side and the receding glacial ice sheet just a few hundred miles to the north. The ridge would probably have remained much colder than the mainland, offering a refuge in a slowly warming world for animals and vegetation adapted to very cold environments.
Such isolated pockets of archaic ecosystems that endure after broad continent-wide climate shifts are known as refugia. And if herds of caribou had once migrated across this landscape, he reasoned, there were probably people hunting them.
But then again, as you know, Paul, in science, you have to try and hope you are right.
References Generic Radiometric Dating The simplest form of isotopic age computation involves substituting three measurements into an equation of four variables, and solving for the fourth. The equation is the one which describes radioactive decay: The variables in the equation are: Pnow – The quantity of the parent isotope that remains now. This is measured directly. Porig – The quantity of the parent isotope that was originally present.
Age of the Universe
These are K-Ar data obtained on glauconite, a potassium-bearing clay mineral that forms in some marine sediment. Woodmorappe fails to mention, however, that these data were obtained as part of a controlled experiment to test, on samples of known age, the applicability of the K-Ar method to glauconite and to illite, another clay mineral.
He also neglects to mention that most of the 89 K-Ar ages reported in their study agree very well with the expected ages. Evernden and others 43 found that these clay minerals are extremely susceptible to argon loss when heated even slightly, such as occurs when sedimentary rocks are deeply buried. As a result, glauconite is used for dating only with extreme caution. The ages from the Coast Range batholith in Alaska Table 2 are referenced by Woodmorappe to a report by Lanphere and others
But apparently it is there.
Richard Cowen’s Chapter Eight: Leaving the Water – images – curent page , , to , , years ago Eurypterids, otherwise known as sea scorpions. Wikipedia Late Ordovician survivals and extinctions: There were no land animals and extinctions were confined to water life. There were two distinct extinctions roughly a million years apart. The first of these began about million years ago.
Together, these extinctions may have removed about 85 percent of species of marine animals.
March, 31 Note: This program originally aired under the title “Last Extinction. Before the last Ice Age, great mammals ruled the plains of North America: You can’t see anything like it today.
Henke referenced Davis A.
Research into glaciation cycles began in the 19th century, but scientists still can’t agree on why ice ages occur. Now there’s new evidence that a cold epoch is in the wings. Those of us who live in the Midwest United States seem to have the worst of both worlds. Hot humid summers, where the temperature often reaches 95 degrees, and cold winters where the mercury can plummet to zero. Despite these seemingly unbearable extremes, we live in a land of plenty because of the most fertile soil in the world, courtesy of the Great Ice Age.
Walls of Snow and Ice According to scientists, over the course of the last two million years, at least four possibly six , periods of glaciation ploughed out an assortment of rock from Canada, moved it south in a foot high flow of ice and snow, pulverized it against bedrock, and deposited it on the Midwest plain. The ice sheet produced large quantities of gravel, sand, and silt.
A mixture of these materials, called till, forms much of the soil in the Ohio and Upper Mississippi River valleys. Remnants of these vast sheets of ice can still be seen today in the form of numerous lakes that pepper the northern regions of the Midwest.