Friday, 22 May 2015
Monday, 18 May 2015
Biogeography: Where Life Lives
http://www.pbslearningmedia.org/resource/nvev-sci-biogeography/biogeography-where-life-lives/
http://www.pbslearningmedia.org/resource/nvev-sci-evolab/nova-evolution-lab-game/
Learn about biogeography, the study of the geographic distribution of organisms, with this video from NOVA’s Evolution Lab. When a new island forms, winds and currents can bring life ashore from nearby land masses. Over time, these organisms evolve into different species. Some species are quite unique, but others have similar relatives around the world. How can a plant in the Pacific Islands be so similar to a South American plant? Organisms could move around easily when Earth’s land masses still formed the supercontinent Pangaea. When the continents split, some species were divided across multiple continents, leading to very similar descendants in distant locations.
NOVA Evolution Lab Game
Create phylogenetic trees and explore genetic relationships between species with NOVA's Evolution Lab. What could you possibly have in common with a mushroom, or a dinosaur, or even a bacterium? More than you might think. In this Lab, evaluate similarities in the traits and DNA of species, and conduct your own investigations in an open-ended interactive tree of life. Along the way, watch short animated videos that explain the evidence for evolution and illustrate it with specific examples. Come climb around the tree of life and see evolution—what some have called the greatest show on Earth—in action.http://www.pbslearningmedia.org/resource/nvev-sci-evolab/nova-evolution-lab-game/
Sunday, 17 May 2015
Saturday, 16 May 2015
Thursday, 14 May 2015
Types of volcanoes.
http://kidspressmagazine.com/science-for-kids/misc/misc/types-volcanoes.html
A volcano is a point or a long crack out of which ash, rock, gases, and lave (molten rock) can travel. When material comes out of a volcano in an explosive, violent way, it is called an eruption. Let’s look at the main types of volcanoes on the Earth.
Fissure Vents – A fissure is a crack, and a volcanic fissure is a crack that lava comes out of. These fissures may form on land, on the sides of other volcanoes or lava fields, or underwater at spreading zones where tectonic plates move away from each other.
Shield Volcanoes – Shield volcanoes form over “hotspots” where magma in the earth’s mantle becomes extra-hot and flows upward to the crust. Lava generally flows out slowly, though these volcanoes can also erupt, sending lava and gas into the air. They are usually big, low, and curved, like the shape of a knight’s shield.
Cinder Cones – These are usually small but steeper-sided volcanoes that also form in relation to hotspots. Cinder cones are more explosive than shield volcanoes. When the cinder cone erupts, it blasts hot lava and ash up into the air where it cools rapidly and falls to stick on to the cone’s slopes, rather than just leaking out like a shield volcano.
Stratovolcanoes – Stratovolcanoes are volcanic mountains that build up in successive layers of different kinds of rock. These are usually found inland of subduction zones, where the water-rich rock of a heavy oceanic plate gets pushed under a continental plate, melted, and then rises up to the continental surface. Different types of melted rock, mixed with the explosive build-up of steam, build the layers of these volcanic slopes. Stratovolcanic eruptions are the most powerful and dangerous type, releasing lava flows, pyroclastic flows, ash, and even bombs (large flying rocks).
A volcano is a point or a long crack out of which ash, rock, gases, and lave (molten rock) can travel. When material comes out of a volcano in an explosive, violent way, it is called an eruption. Let’s look at the main types of volcanoes on the Earth.
Fissure Vents – A fissure is a crack, and a volcanic fissure is a crack that lava comes out of. These fissures may form on land, on the sides of other volcanoes or lava fields, or underwater at spreading zones where tectonic plates move away from each other.
Shield Volcanoes – Shield volcanoes form over “hotspots” where magma in the earth’s mantle becomes extra-hot and flows upward to the crust. Lava generally flows out slowly, though these volcanoes can also erupt, sending lava and gas into the air. They are usually big, low, and curved, like the shape of a knight’s shield.
Cinder Cones – These are usually small but steeper-sided volcanoes that also form in relation to hotspots. Cinder cones are more explosive than shield volcanoes. When the cinder cone erupts, it blasts hot lava and ash up into the air where it cools rapidly and falls to stick on to the cone’s slopes, rather than just leaking out like a shield volcano.
Stratovolcanoes – Stratovolcanoes are volcanic mountains that build up in successive layers of different kinds of rock. These are usually found inland of subduction zones, where the water-rich rock of a heavy oceanic plate gets pushed under a continental plate, melted, and then rises up to the continental surface. Different types of melted rock, mixed with the explosive build-up of steam, build the layers of these volcanic slopes. Stratovolcanic eruptions are the most powerful and dangerous type, releasing lava flows, pyroclastic flows, ash, and even bombs (large flying rocks).
Wednesday, 13 May 2015
Submarine volcanoes
http://ocean.si.edu/ocean-videos/submarine-volcanoes-erupting
Did you know that 80 percent of the volcanic eruptions on Earth take place underwater?
These underwater eruptions occur regularly, forming
new landmasses and providing a living environment for deep-sea creatures.
In 2009, scientists discovered the deepest ocean eruption ever found—the West Mata Volcano.
Explore other videos that capture the beauty and mystery of the ocean realm at NOAA Ocean Today.
Did you know that 80 percent of the volcanic eruptions on Earth take place underwater?
In 2009, scientists discovered the deepest ocean eruption ever found—the West Mata Volcano.
Explore other videos that capture the beauty and mystery of the ocean realm at NOAA Ocean Today.
