La mayoría de países del planeta experimentará fuertes cambios en su climatología que afectarán incluso su subsistencia.
"La Tierra no es una herencia de nuestros padres, sino un préstamo de nuestros hijos."
I thought it might be nice to share a little snapshot of a sample lesson with you. If you've never used my curriculum guides before, this is what you get.
Explore LL Brr's 162 photos on Flickr!
I thought it might be nice to share a little snapshot of a sample lesson with you. If you've never used my curriculum guides before, this is what you get.
Have your students fill in a blank Bingo card with amino acids - there aren't enough amino acids to fill a regular 5x5 card, so allow studen...
Passage 1: Andrea Palladio. Italian architect - Passage 2: Pottery production in ancient Akrotiri - Passage 3: The future never dies?
A difference between endothermic and exothermic processes.
Explore LL Brr's 162 photos on Flickr!
Una buena infografia para primaria tiene elementos claves que generan la información precisa, los temas suelen cambiar dependiendo del grado escolar.
Students learn about landslides, discovering that there are different types of landslides that occur at different speeds — from very slow to very quick. All landslides are the result of gravity, friction and the materials involved. Both natural and human-made factors contribute to landslides. The interactions and different severity of these variables are demonstrated in the associated activity where students learn how scientists are studying landslides and current efforts to prevent them.
La mayoría de países del planeta experimentará fuertes cambios en su climatología que afectarán incluso su subsistencia.
"La Tierra no es una herencia de nuestros padres, sino un préstamo de nuestros hijos."
How Do Plate Boundaries Form and Die? The configuration of plates and plate boundaries visible on our planet today has not existed for all of geologic history, and will not exist indefinitely into the future. Because of plate motion, oceanic plates form and are later consumed, while continents merge and later split apart. How does a new divergent boundary come into existence, and how does an existing convergent boundary eventually cease to exist? Most new divergent boundaries form when a continent splits and separates into two continents. We call this process rifting. A convergent boundary ceases to exist when a piece of buoyant lithosphere, such as a continent or an island arc, moves into the subduction zone and, in effect, jams up the system. We call this process collision. Continental Rifting During the process of rifting, lithosphere stretches. A continental rift is a linear belt in which continental lithosphere pulls apart (figure above a). During the process, the lithosphere stretches horizontally and thins vertically, much like a piece of taffy you pull between your fingers. Nearer the surface of the continent, where the crust is cold and brittle, stretching causes rock to break and faults to develop. Blocks of rock slip down the fault surfaces, leading to the formation of a low area that gradually becomes buried by sediment. Deeper in the crust, and in the underlying lithospheric mantle, rock is warmer and softer, so stretching takes place in a plastic manner without breaking the rock. The whole region that stretches is the rift, and the process of stretching is called rifting. As continental lithosphere thins, hot asthenosphere rises beneath the rift and starts to melt. Eruption of the molten rock produces volcanoes along the rift. If rifting continues for a long enough time, the continent breaks in two, a new midocean ridge forms, and sea-floor spreading begins. The relict of the rift evolves into a passive margin. In some cases, however, rifting stops before the continent splits in two; it becomes a low-lying trough that fills with sediment. Then, the rift remains as a permanent scar in the crust, defined by a belt of faults, volcanic rocks, and a thick layer of sediment. A major rift, known as the Basin and Range Province, breaks up the landscape of the western United States (figure above b). Here, movement on numerous faults tilted blocks of crust to form narrow mountain ranges, while sediment that eroded from the blocks filled the adjacent basins (the low areas between the ranges). Another active rift slices through eastern Africa; geoscientists aptly refer to it as the East African Rift (figure above c, d). To astronauts in orbit, the rift looks like a giant gash in the crust. On the ground, it consists of a deep trough bordered on both sides by high cliffs formed by faulting. Along the length of the rift, several major volcanoes smoke and fume; these include the snow-crested Mt. Kilimanjaro, towering over 6 km above the savannah. At its north end, the rift joins the Red Sea Ridge and the Gulf of Aden Ridge at a triple junction. Collision India was once a small, separate continent that lay far to the south of Asia. But subduction consumed the ocean between India and Asia, and India moved northward, finally slamming into the southern margin of Asia about 40 to 50 million years ago. Continental crust, unlike oceanic crust, is too buoyant to subduct. So when India collided with Asia, the attached oceanic plate broke off and sank down into the deep mantle while India pushed hard into and partly under Asia, squeezing the rocks and sediment that once lay between the two continents into the 8-km-high welt that we now know as the Himalayan Mountains. During this process, not only did the surface of the Earth rise, but the crust became thicker. The crust beneath a collisional mountain range can be up to 60 to 70 km thick, about twice the thickness of normal continental crust. The boundary between what was once two separate continents is called a suture; slivers of ocean crust may be trapped along a suture. Continental collision (not to scale). Geoscientists refer to the process during which two buoyant pieces of lithosphere converge and squeeze together as collision (figure above a, b). Some collisions involve two continents, whereas some involve continents and an island arc. When a collision is complete, the convergent plate boundary that once existed between the two colliding pieces ceases to exist. Collisions yield some of the most spectacular mountains on the planet, such as the Himalayas and the Alps. They also yielded major mountain ranges in the past, which subsequently eroded away so that today we see only their relicts. For example, the Appalachian Mountains in the eastern United States formed as a consequence of three collisions. After the last one, a collision between Africa and North America around 300 Ma, North America became part of the Pangaea supercontinent. Credits: Stephen Marshak (Essentials of Geology)
by Morgan Haldeman and Mikaela Reisman How did Arizona’s Grand Canyon Form? Few places can come close to approximating the appearance of the Colorado Plateau. However, they are not nearly as large, nor can they replicate the conditions of its formation (borrowed from Ranney, 2012): Thick stack of stratified rock. Varied and vivid color within the […]
