Atmosphere and Hydrosphere (Sci 10 Geol 2 PDF)

**Atmosphere and Hydrosphere** **Atmosphere** **What is the atmosphere?** - Gaseous layer that surrounds the Earth - Mixture of gases that compose the atmosphere is known as **air.** **Origin of the Atmosphere** - Early atmosphere was formed by the release of gases. - Early atmosphere...

**Atmosphere and Hydrosphere** **Atmosphere** **What is the atmosphere?** - Gaseous layer that surrounds the Earth - Mixture of gases that compose the atmosphere is known as **air.** **Origin of the Atmosphere** - Early atmosphere was formed by the release of gases. - Early atmosphere was composed of - Methane, ammonia, water vapor, and neon - 10x to 200x more carbon dioxide - Unicellular organisms helped provide oxygen in the atmosphere **Atmosphere's Composition** **Permanent Gases** - Nitrogen (N2) - Oxygen (O2) - Argon (Ar) Some gases' concentration changes - Water vapor (H2O) - Carbon dioxide (CO2) - Methane (CH4) - Ozone (O3) - Other trace gases In practice, air also contains water vapor - **Humidity** - This varies according to temperature and geographical characteristics of the area In practice, air also contains solid particles - **Aerosols** - Salt, Sand, smoke, ash Water vapor and aerosols are responsible for for most atmospheric phenomena **Distribution of Air** - Majority of air is concentrated near the surface - As altitude increases, the air becomes less dense.  **Layers of the Atmosphere** A diagram of the earth\'s atmosphere Description automatically generated **Troposphere --** Lowest part of the atmosphere. Contains most of our weather -- clouds, rain, snow. Temperature gets colder as the distance above the earth increases by about 6.5 C/km. The troposphere contains about 75% of all of the air in the atmosphere and almost all of the water vapor, (which forms clouds and rains). The decrease in temperature wit height is a result of the decrease in pressure. - **Boundary Layer:** lowest part of the troposphere - **Tropopause:** top part of the troposphere **Stratosphere:** Extends upwards from the tropopause to about 50km. Contains much of the ozone in the atmosphere. Increase in temperature with height occurs because of absorption of UV radiation. **Mesosphere:** Region above the stratosphere. Temperature decreases with height reaching a minimum of about 90C at the mesopause. Extends to 85 km. ***Karman line:** boundary separating Earth's atmosphere and outer space. The line is neither sharp nor well defined but is often taken to encircle the Earth at an altitude between 80 to 100 km.* **Thermosphere and ionosphere:** Lies above the mesopause. Temperature increase is caused by the absorption of energetic UV and X-Ray radiation from the sun. **Exosphere:** Region above about 500 km. Contains mainly oxygen and hydrogen atoms. They follow ballistic trajectories under the influence of gravity and few of them rarely collide. Some escape right into space. **Role of the Atmosphere** **Main Functions:** - Generates necessary pressure for liquid water to exist - Absorbs significant amount of UV radiation. - Averages temperature differences between day and night. **The Greenhouse Effect** Seasons exist because - Variations in the length of daylight - Variations in the angle of the sun's rays - Variation of atmosphere's thickness being traversed by sun's rays. The greenhouse effect is a process that occurs when gases in Earth\'s atmosphere trap the Sun\'s heat. This process makes Earth much warmer than it would be without an atmosphere. The greenhouse effect is one of the things that makes Earth a comfortable place to live.  A diagram of a greenhouse effect Description automatically generated Solar radiation passes through the clear atmosphere. Most radiation is absorbed by the earth's surface and warms it. Some solar radiation is reflected by the earth and the atmosphere. Some of the infrared radiation passes through the atmosphere and some is absorbed and re-emitted in all molecules. The effect od this is to warm the earth's surface and the lower atmosphere. Infrared radiation is emitted from the earth's surface. **Interactions with the Atmosphere** **Biosphere:** Oxygen, Carbon Dioxide **Hydrosphere:** Weather & Climate, Energy **Geosphere:** Rock cycle **Climate of Baguio City** Dry season from **November** to **April,** wet season from **May** to **October** Baguio receives an annual precipitation load of about 4000m, which is among the highest loads in the country Located in a mountainous area with an elevation ranging from 900 to 1,600 meter. **Carbon Cycle** Nature's way of recycling carbon atoms Chemical backbone of life.  1. **Photosynthesis by Producers:** Plants absorb CO2 from the atmosphere and use sunlight to produce glucose and oxygen 2. **Plant and Animal Respiration**: Plants and animals release CO2 back into the atmosphere 3. **Carbon Fixation by Consumers:** Herbivores, like the cow, consume plants and transfer carbon through the food chain 4. **Decomposition:** Decomposers break down the organic matter of dead plants and animals, releasing carbon into the soil 5. **Fossil Formation and fossil fuels:** carbon from dead organisms form fossil fuels like coal and oil under heat and pressure 6. **Fossil Fuel Combustion**: Humans extract and burn fossil fuels, releasing CO2 back into the atmosphere 7. **CO2 in the atmosphere:** CO2 released into the atmosphere is absorbed by plants through photosynthesis **Hydrosphere** **Hydrosphere:** includes water that is on the surface of the planet, underground, and in the air. A diagram of water cycle Description automatically generated Water cycle 1. **Evaporation:** The sun heats water in the bodies of water, turning into water vapor, which rises into the atmosphere. 2. **Transpiration:** Plants absorb water through their roots, it is released into the atmosphere as water vapor through small openings in their leaves. 3. **Condensation:** Water vapor rises into the atmosphere, cools, and changes into tiny water droplets, forming clouds. 4. **Precipitation:** Water droplets in clouds combine, becoming heavy and falling back to Earth as precipitation in the form of rain, snow, hail or sleet. 5. **Snowmelt Runoff:** Precipitate that doesn't infiltrate the grounds flows across the land's surface into rivers, lakes, or oceans. **Origin of the Hydrosphere** - Formed around the same time as the atmosphere - Earth did not have water or water vapor at its surface - Water came from meteorites or comets during the late heavy bombardment period. - Chemical reactions in the Earth's interior - Volcanic activity on early Earth played a key role in releasing water - Early hydrosphere formed from volcanic activity - As the Earth cooled, water vapor in the atmosphere condensed and fell as in rain. - Minerals in the crust that held water. **Distribution of Water** - **71%** of Earth's surface is covered in water - Oceans hold about 96.5% of all Earth's water.  ***Where does Baguio City Get its Water?*** **85%** Groundwater and the rest from watersheds **Properties of the Hydrosphere** **Rainwater** - Rainwater is not pure - Dissolved gasses and salts, particulate matter, bacteria - From oceans, soils, fertilizers, air pollutants - atmosphere-precipitation-evaporation-atmosphere turnover is 9.6 days **Groundwater** - Water that exists underground - Not from underground rivers - Fills pores and fractures present in the sand, gravel, and other rocks - Aquifer: the rock where groundwater flows or is pumped out of. - Move slowly (7-60 cm per day) A diagram of land surface Description automatically generated **Rivers and Ocean water** - **Salinity --** dissolved salt content of a body of water - Sea water contains about 3.5% dissolved salts - River water contains only 0.012% dissolved salts - 6 abundant ions in seawater - Chloride: 55% - Sodium: 31% - Sulfate: 8% - Magnesium: 4% - Calcium: 1.2% - Potassium: 1.1% **Ocean Water** - Ocean surface-water temperature vary from -2 C to 36 C - Temperature decreases, salinity, and pressure  **Thermocline:** layer where temperature decreases rapidly with depth **Halocline:** layer where salinity changes rapidly with depth **Pycnocline:** Layer where water density increases rapidly with depth **Water-Rock Interactions** **River water & Lakes** - Water weathers rocks - In general, the composition of river water and lakes depends on the surrounding rocks 1. Change in the ions present in water 2. Mobility of different elements 3. Groundwater may be affected **Mining Industry** **Mine Tailings** - Physical and chemical separation of metal from the ore - Mining waste materials **Gold mine tailings have an effect on health, agriculture, and environment** - Cancer in children and adults **Building Dams** **Kaliwa Dam** - Illegal and immoral - Building a dam requires flooding the area **Dams can:** Affect migration, alter habitat, and affect water quality