History of an ocean people often think about the age of something by watching changes over time (e. g., pictures of you as a baby, child, and adult). however, this technique does not work in geology because we cannot watch something change over millions of years. one way to solve this problem as it relates to oceans is to look at the oceans and put them in order of how old they are today (e. g., compare a toddler in one city to a leen in another city). 5. match the diagrams from the previous page, which illustrate the stages of an ocean, to the five locations listed below. place the letter next to the stage of ocean formation. east african rift atlantic ocean 2 atlantic ocean himalayas red sea pacific ocean pacific ocean 4. african pacific ocean 6. take your answers to questions 3 and 5 and place the locations on earth in order from the youngest to the oldest in the life cycle of an ocean. youngest oldest 7. two students are debating the locations on earth and their order in the stages of an ocean. student 1: i think the himalayas are the very end of an ocean. they formed as a result of a convergent boundary, so the plates are coming together, which means the ocean that was once there completely shrunk away into nothing. student 2: no. i think the himalayas are the very beginning of an ocean because they are the highest, and then the crust would get thinner and thinner until it becomes an ocean, and the ocean would then grow bigger. with which student do you agree? why? 8. revise the order of your ocean stages in questions 3 and 6 if necessary. 9. predict what the red sea will look like in 100 million years. 10. predict what the east coast of the united states could look like in 100 million years. w. h. freeman and company lecture tutorials for introductory geoscience 41. history of an ocean below are cross sections of an ocean at different stages of its life cycle, from pre-ocean to post-ocean. the ocean surface is indicated by a dashed line. ocean lithosphere continental lithosphere 1. describe the one plate boundary shown in b. is the ocean growing or shrinking? bis divergent plate boundaries showing mid-occonec ridge. where lava is erupting and construding the plate abo the oceanis eccponding 2. describe the two plate boundaries shown in e. is the ocean growing or shrinking? e two plate boundaries are convergent plate bound oues. where occanie plates are subducting below the continental plate, this plate boundary is also knoeing, destructive .plate boundaries, the one of 3. arrange the five diagrams in sequentiat order from pre-ocent post-ocean. write your order below. youngest a d b e c oldest 4. two students are debating the order of the stages of an ocean. student 1: i put the cross sections in order from the smallest ocean to the biggest: c-a-d-e-b. i did this because the ocean is growing bigger over time. student 2: but you need to look at the plate boundaries for clues. e has subduction happening, so that means the ocean is shrinking, and that means it was once bigger with which student do you agree? why? i agree with student 2 because the first ocean is created from the continent and then oceanic late gets subducted and at last being two continents to gethere and collisim may or may not happen to forma mountain belt. © w. h. freeman and company lecture tutorials for introductory geoscience 40.