Earth Science Regents Review Unit 4 It is the physical break down of rocks into smaller pieces. It is the breakdown of rocks by changing their chemical composition and making them weaker. Frost Wedging: Water seeps into cracks, freezes then widens the crack until it breaks the rock. The chipping off of sharp edges of rocks. Oxidation: When oxygen combines with a metal in the presence of water. It is the amount of space the surfaces take up. The greater the surface area the faster the weathering. Heat speeds up reactions so the more heat and water present the faster the reaction. 1) Define erosion: The process where weathered fragments are carried away. 2) Agents of Erosion _______________ Abrasion by sand Carries small particles Pitted surface 6 _____________________ Faster flow = more power #1 agent of erosion Rounded particles “V”- shaped valleys Fastest in the middle just below the surface __________________ “U”-shaped valley “rivers of ice” Striations (scratches in bedrock) Erratics (boulders in odd places) _______________________ Driving force of all agents Jagged edges What moved each of these sediments? How do you know? Aim: How do soils form? 1) What are the three ways a river can carry sediments? Pebbles, Cobbles and Boulders Halite and Calcite Silt and Clay 3) What is the relationship between the speed of a river and the size of the particle that it can carry? The faster the river, the bigger the particle it can carry. 4) What makes a stream flow fast? (a) (b) Stream discharge_________________________ Gradient________________________________ 5) What is a meander and how does it tell you about the shape of the land? A meander is a bend in a river. These bends form when the land is flat. 6) How does water flow in a meander? It flows fastest on the outside (erosion) and slowest on the inside (deposition) of the bend. Exit Card 1) Draw the shape of the side view of the river from point 1 to point 2. Use p. 6 of the ESRT’s to answer the following question 2) How fast does a river have to travel to carry sediments 0.2 cm in diameter? 1) What is beach erosion? • It is the disappearance of a beach and its sand due to longshore drift. 2) What is longshore drift? • The migration of sand downshore by waves crashing onto the beach. 4) What is a groin and what is its purpose? • A groin is a structure set perpendicular to a beach to slow the migration of sand. 5) How can you tell which way the ocean current is flowing? • The current is coming from the same side of the groin as the sand. Which way is the longshore drift? Today’s Exit Card • 1) What problems does beach erosion cause? Diva Dollar Question • Which direction is the longshore drift coming from? How can you tell? 2) When did the last glaciation of New York occur? About 10,000 years ago during the Pleistocene epoch. 4) What are moraines? Large piles of unsorted sediment left at the front or sides of a glacier. 5) Where does a glacier move the fastest? Glaciers move fastest in the middle at the surface. 6) What four features do glacial landscapes have? (a) U-shaped valley (b) unsorted sediments (c) striations (d) erratics • 1) Deposition is the settling of eroded sediments. 3) Factors which affect the rate of deposition: Factor Relationship • 5) ______________ largest sizes on the bottom and the smallest on the top. • 5) ______________________: largest sizes close to the shore and the smaller sediments farther out. Horizontal Sorting 8) Do glaciers sort sediment? • No, glaciers do not sort sediments. They just push them into piles and scratch them. 1) Define delta A fan shaped deposit of sediments that form when the mouth of a river enters the ocean. 3) What are oxbow lakes and how do they form? These are cut off sections of a river formed as a river erodes the outsides and deposits on the insides of meanders. Stream Drainage Patterns • A: Dendritic: flat land; random branches • B: Trellis: folded rocks of different resistance • C: Rectangular: faulted rocks (water flows in cracks) • D: Radial: mountain or volcano 3) What features separate one landscape from another? A) bedrock structure B) relief C) stream patterns D) slope of the land E) type of soil 5) What are the three types of landscapes? ________________ Flat area (low relief) Low elevation Small hills Mostly sedimentary Kansas or Long Island __________________ Middle relief Horizontal layers Flat with deep valleys (think Road Runner) Grand Canyon (Arizona) _________________ High relief High elevation Metamorphic Non-horizontal layers Steep slopes Rocky Mountains 6) How does climate affect landscapes? (a) Humid= chemical weathering= smooth slopes and lots of vegetation (b) Arid= physical weathering= steep slopes, rocky, sharp and less vegetation