science

• Weathering refers to the process of breaking down rocks into smaller pieces. Several forces can change the physical and chemical characteristics of rocks near Earth's surface.

  
• Physical or Mechanical Weathering

  • Rocks break down by changing their physical appearance
  • Rocks break down by changing their chemical composition

  
• Freeze-Thaw Action


  1. Rocks exposed to intense heat crack or crumble when rain falls

  2. Water accumulates in cracks or crevices

  3. Expansion is brought about by freezing temperature making cracks deeper and wider

  4. As temperature rises, frozen water washes off sediments

  
• Plant Root Growth


  1. Roots find their way into cracks in rocks

  2. As roots grow bigger or longer, the crack becomes wider

  3. Rock finally splits and breaks apart
• Chemical Weathering


  • Certain elements react with oxygen (oxidation)
  • Elements in rocks become oxides and their properties change
  • Oxidation can cause elements composing minerals to decompose and form new minerals
• Weathering is the process of soil formation.
• Disintegration is also known as physical or mechanical weathering.
• Rocks on the surface of the Earth do change.
• When water freezes it expands and exerts more pressure on the rocks causing it to break.
• Disintegration is a mechanical process that breaks rocks into smaller pieces.
• Weathering has effects on your life

  Positive effects: Helps make soil more fertile, provides building materials, plays a role in formation of new landscapes and landforms, exposes new minerals

  Negative effects: Damage to monuments and historical buildings, causes rust, cracks and imperfections, acid rain causes damage to living things and inorganic matter
• Uses of rocks and minerals


  • Sand, gravel, and stone for construction and building materials
  • Metallic minerals, particularly iron, used in production of cars, planes, and boats
  • Structures and outdoor furniture made of mineral or rocks
  • Arts and crafts made using beautiful rocks and minerals
• Formation of Soil


  1. Layer of rock and mineral fragments produced by weathering covers Earth's surface

  2. Broken fragments do not become high-quality soil until plants and animals live in them

  3. Organic matter includes leaves, twigs, roots, dead worms and insects

  4. Soil is a mixture of weathered rock, decayed organic matter, mineral fragments, water, and air

  5. Soil can take thousands of years to form and can range from 60 cm thick to just a few centimeters thick

  6. Climate, slope, type of rock, type of vegetation, and length of time rock has been weathering affect soil formation
• Hurricane


  A type of tropical cyclone
• Typhoon


  A type of tropical cyclone
• Tropical cyclone


  • Forms when the water is warmer than the surrounding area, with temperature higher than 26°C
  • Warm moist air above rises, creating a low-pressure area
• Formation of tropical cyclone

  1. Warm moist air rises

  2. Creates low-pressure area

  3. Wind from surrounding area spirals counterclockwise (northern hemisphere) or clockwise (southern hemisphere) due to Coriolis effect

  4. Continuous supply of rising moist air

  5. Abundance of warm seawater to continuously feed the rising air with moisture

  6. Temperature of the ocean should be 80°F or 27°C

  7. Air at the center must rise high enough and the exit must be continuous to permit a flow of rising air from below
• what is The calm center of a typhoon

  eye
• Wind


  An agent of weathering that carries light materials and soil particles by blowing them and depositing them in other places
• Eye wall


  The area surrounding the eye that contains the intense rainfall and cumulonimbus clouds and produces the strongest winds of a typhoon
• Wind erosion


  • It disperses soil particles that cause topsoil loss, crop yields reductions, infrastructure damage, weed dispersal, and dam silting
• Classifications of tropical cyclones by wind speed

  • Tropical depression: Maximum wind speed of not more than 60 km/hr
  • Tropical storm: Maximum wind speed from 60 to 118 km/hr
  • Typhoon: Maximum wind speed is greater than 118 km/hr
• Animals


  • They damage the soil surface by eating vegetation and digging into wet or compacting dry soil with their hooves
• Human activities


  • They damage the soil by doing activities such as gardening, quarrying, mining, deforestation, bad farming, and kaingin
• A typhoon is considered the most destructive weather disturbance because it is characterized by heavy rains and is accompanied by violent winds
• Erosion


  The movement of rock fragments and soil from one place to another
• Erosion is a process of rock particles transportation elsewhere
• Regions in the Philippines prone to typhoons

  • Bicol Region
  • Samar
  • Leyte
  • Quezon Province
  • Nueva Vizcaya
  • Southern Mindanao
  • Southern Visayan Islands
  • Palawan
  • Mindoro
• World Meteorological Organization (WMO)


  Developed a system that gives names to hurricanes to avoid confusion and for clear communication
• Weathering and erosion are the two forces of the Earth's surface constantly at work
• The names are arranged alphabetically
• The origin of the formation or where they hit was used in naming typhoons before
• Weathering occurs so slowly that it is seldomly noticed. Erosion can be more rapid
• Female names were used exclusively in 1953
• The deposition or settling of the finer particles of rock or sediment carried by wind or water can easily be seen
• The Filipino women names was adapted in 1963
• In some cases, weathering and erosion occur simultaneously
• Water erosion


  1. Water is continuously cycled into the air and back

  2. Water joins the oceans, streams, and lakes

  3. Part of the water flows through innumerable rivers and streams and deposits its load in the oceans

  4. Water that sinks into the ground forms groundwater
• Water erosion


  • Water accomplishes the greatest change on Earth by erosion
  • After the rain, the runoff dissolves fine rock particles as it flows
  • Gullies are formed by the surface water
  • As gullies flow, the water removes topsoil
• The use of women's names to typhoons was due to history's common misconception, associating a woman is as fickle as the weather