1. Soil is made up of rock particles (clay, silt, sand, and gravel), minerals, air, water, and organic matter (decayed organic material is called humus).
2. Loam is fertile, good for growing plants. The humus in loam provides nutrients and spaces for air and water--loam is about 25% air and 25% water. Also loam is about equal parts clay, sand, an silt, so the texture of the soil holds in a good amount of water. (Too much clay means too much water and too much sand means it doesn't hold in enough water.)
3. The soil horizons form in the order C, then A, then B. First bedrock is weathered to produce the C horizon (partially weathered rock). Then the C horizon is weathered and plants grow and contribute their parts to the soil which creates the A horizon (topsoil). Then particles from the A horizon (mostly clay and other rock particles) wash down and mix with the C horizon to make the B horizon (subsoil).
4. Humus is dark colored organic matter (made from plants and animals) that is found mostly in the topsoil. When remains of plants and animals decay due to activity of decomposes (like earthworms or bacteria) then humus is formed.r
5. Soil is mixed by organisms in the soil. Burrowing animals and earth worms can mix the soil.
1. Weathering breaks down rock into small particles, or sediment. Forces of erosion (water, wind, ice, or gravity) carry and move these pieces. The earth's surface is constantly changing because some rock is worn away, and then after erosion deposits the rock, new rock can be formed in a different location.
2. Mechanical weathering physically breaks rock into smaller pieces, but chemical weathering breaks rock down through chemical changes.
3 and4. SEE TABLES
5. Two aspects of the type of rock can change the rate of weathering: mineral composition and perm ability.
The mineral composition in important because only some minerals are soluble (able to dissolve) in water. If a rock contains minerals that are soluble in water, then it will weather more quickly.
Permeability is important because if a rock is permeable, water can seep into the rock. Water can then weather the rock more quickly because it can weather the inside of the rock too.
6. Climate can affect the rate of weathering. Weathering occurs more quickly in hotter climate than cold one (because chemical reactions happen faster at warmer temperatures. Weathering also occurs more quickly in wet climate (water is necessary for chemical weathering and for freezing and thawing to occur). The type of climate in which rock weathers the fastest is a hot and wet climate.
On February 27, 2010, and 8.8 magnitude earthquake shook Chile. The epicenter was off the coast of Maule, Chile, 115 km from the more populated city of Concepcion. This epicenter is not far from the epicenter of the 9.5 magnitude 1960 quake.
More info at USGS.gov
Video of Earthquake
1. A shield volcano forms when quiet eruptions over time produce lava flows that run over land (and can spread out) and cool and harden into volcanic rock. Overtime, these layers of volcanic rock build on-top of each other to make a gently sloping shield volcano. (Example: Kilaeua)
2. Composite volcanoes form when repeated eruptions of pyroclastic flow (cooling volcanic rock particles of ash, cinder, and bombs) build up on each other. These are often steep, cone-shaped mountains. (Example: Paricutin)
3. Eruptions of lava flows (quiet) and pyroclastic flow (explosive) alternate to form composite volcanoes. The volcano is then built up of a layer of ash, cinders, and bombs and then a layer of lava over and over again. The volcanoes have a steeper slope at the top and then a gentler slope at the bottom. (Example: Mt. St. Helens)
4. Often the soils produced from volcanic eruptions and volcanic rock are actually high in nutrients and can be good to grow crops.
5. See above
Activity for 2/17-2/18:
At the summit:
The lava levels in the pit of Halema`uma`u crater were low, but the lava was still moving around inside the crater. At 7 AM a hybrid earthquake occurred alogn with rockfalls. At this time the lava level lowered more. Seismic tremors continued at steady levels and two earthquakes below Kilauea were large enough to be located.
The tiltmeter recorded DI deflation and a a "positive offset" at 7AM when the hybrid earthquake occurred. The GPS receivers also indicated contraction (they came closer together which confirms that deflation is occurring).
At the east rift zone:
The tiltmeter at Pu`o`O`o crater also recorded DI deflation. Pahoehoe lava flowed down the flow fields.
The Hawaiian volcano Observatory Page updates their info with images of tiltmeter and GPS recordings. Click here to see the recording. Post below by either explaining what the tiltmeter data shows occurred during the past few days in February OR explain what the GPS receiver show has occurred since March 2008.
Activity at Kilaeua 2/16-2/17:
Click here to see a picture of a gas plume at the Haleuma`u crater, at the summit of Kilauea.
Currently, at the summit of Kilauea 900 tonnes per day of sulfur dioxide (SO2) gas is being released into the air. Between the years of 2003 and 2007 the average amount of sulfur dioxide released a day was only 140 tonnes per day.
In order to respond to this post click here and read about volcanic gases. Respond with a post that describes at least one effect of SULFUR DIOXIDE (SO2) GAS.
