Weather - Interactive New Englanders have a saying: "If you don't like the weather, just wait a minute." Weather forecasts may be more stable in other parts of the world, but the basic idea stands. Weather is dynamic, the product of interacting forces we are only beginning to understand. Witness the weather extremes caused by El Niño in 1997 and 1998. El Niño raised water temperatures in the Pacific and the effects were felt worldwide: crop failures, disease outbreaks, excess snow, or too little rain. Weather may change on a daily basis, but climate changes over geologic time. Join us as we explore the forces behind the weather.
History of deadly earthquakes Image copyright Getty Images Earthquakes have claimed hundreds of thousands of lives in the last 100 years, and improvements in technology have only slightly reduced the death toll. 25 April 2015 A 7.8-magnitude earthquake kills more than 8,000 people and leaves hundreds of thousands homeless, in the worst natural disaster to strike Nepal since 1934. In some parts of the country, the quake flattens 98% of all homes in hillside villages. 3 August 2014 Approximately 600 people are killed in a 6.1-magnitude earthquake that strikes Yunnan province in China. 15 October 2013 More than 200 people are reported to have died after a magnitude 7.2 earthquake strikes centrally-located Bohol and Cebu in the Philippines. 25 September 2013 More than 300 people are killed as a 7.7-magnitude quake flattens entire villages in Pakistan's remote south-western province of Balochistan, mainly in the district of Awaran. 20 April 2013 11 August 2012 23 October 2011 11 March 2011 22 February 2011 14 April 2010 6 April 2009
The Mayan Calendar - an explanation Cyclical: One of the wheels in the Mayan Calendar ©iStockphoto.com/Xixun Count down to the end of the Mayan calendar using our Mayan Calendar Countdown. The Mayan calendar moves in cycles with the last cycle ending in December 2012. Count down the seconds to “the end” The best doomsday prophecies in history The last day of the Mayan calendar corresponds with the Winter Solstice (or December Solstice), which has played a significant role in many cultures all over the world. The Maya didn't invent the calendar, it was used by most cultures in pre-Columbian Central America – including the Maya – from around 2000 BC to the 16th century. Wheels working together The Mayan Calendar consists of three separate corresponding calendars, the Long Count, the Tzolkin (divine calendar) and the Haab (civil calendar). The three calendars are used simultaneously. The Haab The Haab is a 365 day solar calendar which is divided into 18 months of 20 days each and one month which is only 5 days long (Uayeb).
What are the layers of the earth? Three hundred years ago the famous scientist Isaac Newton calculated, from his studies of planets and the force of gravity, that the average density of the Earth is twice that of surface rocks and therefore that the Earth's interior must be composed of much denser material. We now know that the earth is made up of 4 layers: How do we know about the different layers of the earth? Information today comes from studies of the paths and characteristics of seismic waves from earthquake waves traveling through the Earth, as well as from laboratory experiments on surface minerals and rocks at high pressure and temperature and studies of the Earth's motions in the Solar System, its gravity and magnetic fields, and the flow of heat from inside the Earth. About Seismic Waves What are the different types of Seismic Waves? Seismic waves are waves of energy that travel through the earth, for example as a result of an earthquake, explosion, or some other process that imparts low-frequency acoustic energy.
Europa’s ocean: Evidence of Jupiter’s moon ocean found on the surface. Image credit: NASA/JPL-Caltech He killed Pluto, but he may have just breathed life into Europa exploration. Astronomer Mike Brown*—discoverer of the giant outer-solar-system iceball Eris which is what started the machinery that kicked Pluto out of the planet club—has found some pretty strong evidence that Jupiter’s moon Europa has sprung a leak. Its undersurface ocean may be mixing with the icy surface, making it possible to understand its composition without having to dig down through dozens of kilometers of solid ice. Mind you, we’ve been eyeballing Europa’s ocean as a potential habitat for life for decades. This evidence that the surface ice and undersurface ocean are in intimate contact comes in a series of steps, which I outline below. Image credit: NASA/JPL/Galileo The water is kept liquid by heating via tidal forces, the effects of the gravity of its massive parent planet. The new data taken by Brown and his colleague Kevin Hand indicate that ocean is much like Earth’s: salty.
The Earth and the Moon What's covered here:What are the physical characteristics of the Earth's interior, surface and atmosphere? What are the physical characteristics of the Moon? Where did the Moon come from? Even though you might not think of it as such, the Earth is a planet. Here we're just going to treat it like one. What exactly do we know about the Earth? Geologists use the information obtained in earthquakes. First, we'll tackle the P-waves They are a form of pressure waves and are most similar to sound waves in how they travel (by pushing material) Pressure wave and Primary waves are other names for them. These move in a rather wiggly, transverse motion, sort of what you get if you take a rope and jerk it up and down quickly - a hump will travel down the length of the rope. These and other earthquake waves originate from the focus, which is the actual location of the earthquake's origin. Figure 1. Figure 2. Figure 3. The core of the earth is amazing, but don't let it freak you out! Figure 4.
Plate Tectonics - Crust, Lithosphere, Mantle Topics Plate Tectonics Crust Lithosphere Mantle Density Buoyancy Earth Science Description Explore how plates move on the surface of the earth. Change temperature, composition, and thickness of plates. Discover how to create new mountains, volcanoes, or oceans! Sample Learning Goals Describe the differences between oceanic and continental crust, including their respective properties of density, composition, temperature and thickness.Predict how changes in composition and temperature change crust density and buoyancy.Draw a time series for different types of plate boundaries and their motions, indicating the related surface features.Deduce the type of plate boundary given images or descriptions of surface features.Explain which types of plate boundaries create crust, and which destroy crust Version 1.02
Junk Problem Is More Threatening Than Ever, Report Warns | NASA's Micrometeoroid and Orbital Debris Programs | National Research Council Report There is so much junk in space that collisions could start to increase exponentially, leading to a continuously growing pile of rubble in orbit, a new report warns. The independent report, released today (Sept. 1), surveyed NASA's work to meet the threat of space debris. It was sponsored by NASA, and conducted by the National Research Council, a nonprofit science policy organization. Space debris — an accumulation of broken satellites, spent rocket stages and other junk in orbit — is dangerous because it could hit and damage working satellites, as well as spacecraft like the International Space Station. Furthermore, when two pieces of junk collide, they can break apart into many smaller pieces, significantly increasing the amount of debris in space. It's a problem that will likely become more visible, and urgent, over time. Kessler Syndrome The situation we're in now is called the Kessler Syndrome, a term named after Kessler, in which the amount of debris has reached a critical threshold.
A Dark Earth with a Red Sprite 5 Strangest Facts About Pluto | Pluto Trivia | The Solar System | Space.com Life's Little Mysteries Staff | August 23, 2011 01:18pm ET Pluto is so far away from Earth that everything we know about it can be written down on a couple of 3 x 5 inch index cards. Pluto will come into clearer focus in a few years' time, though, as NASA's New Horizons probe is due to make a close flyby of the dwarf planet in July 2015, marking the first time a spacecraft has ever visited the frigid, faraway world. For now, though, here are the five strangest facts about the former ninth planet in our solar system. Earth 03 Earth 02 Earth 01