Good afternoon to all readers of the Bioblogosphere! To your attention tasks from topic 15 « Research methods and protection of surface and ground waters».
Task formulation 15- 1. Why did English writer, scientist, and futurologist Arthur Clark said: «How earth does not correspond to our planet! How much more correct it would be to say the Ocean». Prove his statement correctness or incorrectness.
The ratio of land to water surface on Earth: the oceanic hemisphere; the continental oceanic hemisphere.
Answer: w hen viewed from space, our planet appears to be a planet of water; more than 3/4 of it is occupied by the water surfaces of oceans, seas, continental reservoirs and glaciers. The hydrosphere’s area changes, reaching 443 million km2 or about 87% of the Earth’s surface in December-February, 510 million km2 .
Task formulation 15- 2. Why is the amount of water in the hydrosphere not the same all the time? It is known that the ocean level during its existence has repeatedly dropped 120-150 m below the current number.
Answer: water accumulated on land by icy mountains - similar in Antarctica and Greenland. During periods of glaciation, the fraction of the Earth’s surface occupied by the World Ocean was reduced by 5%. But the ocean has always prevailed over land.
Task formulation 15- 3. Why is equatorial area of the oceans a relatively cold place on the planet?
Answer: the average ocean surface temperature = +17.8°С, the “hottest” surface near the Pacific Ocean +19.4°С, and the coldest under the ice of the Arctic Arctic –0.75°С. Below 1500 m in the deep layer t varies from 3 to 1°C. Moving vertically down from the mixing layer, through the seasonal and main thermoclines to the deep layer, is accompanied by a constant drop in t and an increase in water density, which ensures greater stability of the system. Mixing does not stop anywhere, it only slows down very much with depth.
Task formulation 15- 4. Why is the biosphere, despite insignificant amount of water in it, the most powerful and complex hydrosphere filter on Earth?
Answer: In the aquatic environment, plants continuously filter water through their surface, and on land they extract water from the soil and remove (transpire) the surface part. So, for the synthesis of 1 g of biomass, higher plants should evaporate about 100 g of water. The most powerful land transpiration systems are forests that can pump the entire mass of hydrosphere water through themselves over 50,000 years; plankton of the ocean filters out all the ocean water for a year, and marine organisms all together - six months. A complex photosynthesis filter works in the biosphere, in which water is decomposed and, together with CO2 , is used in the synthesis of org. compounds for building organisms.
Task formulation 15- 5. Living organisms are 80-90% water. Which human organ contains the largest amount of water? And in which is the smallest? How can it be explained?
Answer: water is distributed throughout the body and organs. The water content of various organs depends on their composition, and ranges from 83% in blood to only 10% in adipose tissue.
Task formulation 15- 6. Name and explain, what environment has the fastest, largest and heaviest animals with a developed musculoskeletal system.
Answer: The largest and heaviest living animals are all cetaceans 190 tons, and thus also the largest living mammals. The fastest land animal is the cheetah, which has a recorded speed of between 109.4 km/h (68.0 mph) and 120.7 km/h (75.0 mph). The peregrine falcon is the fastest bird, and the fastest member of the animal kingdom, with a diving speed of 389 km/h (242 mph).
Task formulation 15- 7. Any spring (even with good water) is not stable, the water in it changes. It looks beautiful, but you can’t drink such water. Why do people have such an attitude towards spring water?
Answer: the springs feed mainly on precipitation, which leaches harmful substances from contaminated soil. Since the sources can pass at different depths through different thicknesses of the earth's rock, the soil is a natural filter for such water. Therefore, the closer the water comes to the surface, the more it is susceptible to various contaminants. The unsanitary situation around the spring and the lack of proper water intake play a role. Rospotrebnadzor recommends conducting such inspections twice a year - in spring and autumn.
Task formulation 15- 8. A gap in general structure of tidal waves: a continuous wall of waves with a 5-10 m gap in the middle, less often up to 50 m. This is a rip current, the most dangerous among all coastal currents. Why is it so dangerous? How should the one behave when he falls into this current?
Answer: during low tide, water cannot gradually return to the open sea due to the sand spit holding it back. The water pressure on the narrow strait connecting the estuary with the sea rises sharply. In this place, a rapid forms, along which water rushes back to the sea at high speed (up to 2.5-3.0 m / s). Once in a rip currents, one should not resist it. It will quickly weaken away from the coast; some time you should swim along the shore, and then return to it at a certain angle or in a straight line, if the breaking current is not felt. You should not swim in the narrow straits between the braids and islands.
Task formulation 15- 9. Michael Fred Phelps II (1985, Baltimore) is an American swimmer, the only 23-time Olympic champion in sports history, a 26-time world champion in a 50-meter pool, and a multiple world record holder. He is an absolute record holder for the number of awards (28) in the history of the Olympic Games. His sports nickname is «Flying Fish». What anatomical features in Phelps's body helped him get high swimming results?
Answer: has a 47th foot size, which is slightly larger than the average for people of his height; disproportionately short legs and a disproportionately long torso compared with an ordinary person, arm span is 203 cm, which is 10 cm longer than his height. In an interview with USA Today in 2012, Phelps, while answering questions about his diet, stated that media reports about a 12,000 kcal diet were a myth. “I have never eaten so much,” said the champion .
Task formulation 15- 10. An shelf cloud appears in the sky when air temperature changes sharply, and warm air currents are higher than cold. Speed and direction of wind, which «spins» clouds into huge cylinders, immediately change. Explain rules of conduct when shelf cloud appears.
Answer: a lot of moisture is needed to form a squall gate, and gale-like winds will give the clouds a tubular shape and extend ahead of the storm. If you notice a flurry gate in the sky, take measures to protect it from strong winds: move away from old rotten trees or structures that may be unstable in case of strong gusts.
Task formulation 15- 11. On hot summer days, people seek salvation from the heat not only near fountains, but also in them. But you can’t swim in the fountains and, especially, drink water from them. Explain why.
Answer: Water in the fountain circulates and is cleaned by grilles only from large objects. With constant use, it forms a coating of rust, algae, salts. High temperature aquatic environment is an ideal place for microbial reproduction. Dogs bathe in the fountains, city birds are carriers of infections. Micro-habitats of water in the fountain: herpes viruses, enteroviruses, coronoviruses, ornithoses (meningopneumonia, serous meningitis), fungi, hepatitis viruses, typhoid fever, zoonoses (leptospirosis, toxoplasmosis), etc. Water in fountains may be contaminated with oil products and other chemicals substances. In addition, in fountains you can be injured (from broken glass, protruding structures) and electric shock.
Task formulation 15- 12. Scientists (Cambridge, Florida) collected sediment samples (800-1000 CE) in Lake Chichancanab on the Yucatan Peninsula in Mexico. It was established that during the study period precipitation amount was annually less than the average annual norm by 41-54%, and during drought peaks it was 70%. This confirms the British scientist’s hypothesis (90's) that climate change led to the collapse of highly developed Mayan civilization. What method of studying water did they use?
Answer:
Task formulation 15- 13. In 2017, scientists from the University of Michigan in a report at the American Chemical Society congress described a method of determining impurities in water with «coffee rings». What is this method based on?
Answer: spots from water of different composition differ significantly from each other, as if every source had fingerprints. If you compile a file of such prints, you can learn about dissolved substances from the "coffee rings". To do this, you would need only a photograph of one dried drop of water. There are many substances in tap water that do not affect stiffness, but alter the quality, taste and smell, or even cause poisoning.
Task formulation 15- 14. Why does water rise at the edges when it enters the sink before it goes down the drain? Why is there a sharp, spasmodic increase in the water level in the open channel during flow transition from a turbulent to a calm state?
Answer: a hydraulic jump is a sharp, spasmodic increase in the water level in an open channel when the flow changes from a turbulent state to a calm one. For example, when a stream of water flows out from under a dam on a river. So, at the very beginning of the channel behind the dam, the water level is lowered, and at a certain distance from it it rises. The calculation of the hydraulic jump equation was carried out in 1838 by the French engineer, mathematician and hydromechanic Jean-Baptiste Belange (1790-1874).
Thank you for attention! That's all for today! Bye Bye! Have a good day! Take eco-knowledge from me, but give me a like :-)))