Question

geometry a

1. base your answer to the following question on the map of the mid-atlantic ridge shown below. points a through d are locations on the ocean floor. line xy connects locations in north america and africa.

samples of ocean-floor bedrock were collected at points a, b, c, and d. which sequence show the correct order of the age of the bedrock from youngest to oldest?
(1) $c \
ightarrow b \
ightarrow d \
ightarrow a$ (3) $a \
ightarrow d \
ightarrow b \
ightarrow c$
(2) $a \
ightarrow b \
ightarrow d \
ightarrow c$ (4) $d \
ightarrow c \
ightarrow b \
ightarrow a$

1. on which plate is the hawaiian islands located?

(1) nazca (3) pacific
(2) south american (4) antarctic

1. active volcanoes are most abundant along the

(1) equatorial ocean floor
(2) $23.5^\circ$ n and $23.5^\circ$ s parallels of latitude
(3) edges of tectonic plates
(4) eastern coastline of continents

Explanation:

Question 3

Step1: Recall Ocean Floor Bedrock Age Principle

Ocean - floor bedrock near mid - ocean ridges (like the Mid - Atlantic Ridge) is younger, and as we move away from the ridge, the bedrock gets older. The Mid - Atlantic Ridge is a divergent boundary where new oceanic crust is formed. So, the closer a point is to the Mid - Atlantic Ridge, the younger the bedrock at that point.
Looking at the points A, B, C, D: Point C is closest to the Mid - Atlantic Ridge, then B, then D, and then A (the farthest from the ridge). So the order from youngest to oldest should be \(C
ightarrow B
ightarrow D
ightarrow A\).

Step2: Match with the Given Options

Option (1) is \(C
ightarrow B
ightarrow D
ightarrow A\), which matches our deduction.

Step1: Recall Plate Tectonics and Hawaiian Islands Location

The Hawaiian Islands are located on the Pacific Plate. The Nazca Plate is off the west coast of South America, the South American Plate is under South America, and the Antarctic Plate is around Antarctica.

Step2: Match with the Given Options

Option (3) is Pacific, which is the correct plate for the Hawaiian Islands.

Step1: Recall Volcano Formation and Tectonic Plates

Active volcanoes are most abundant along the edges of tectonic plates. At convergent plate boundaries (where one plate subducts under another) and divergent plate boundaries (where plates move apart), volcanic activity is common. The equatorial ocean floor, the \(23.5^{\circ}\text{N}\) and \(23.5^{\circ}\text{S}\) parallels, and the eastern coastline of continents are not the main areas for active volcanoes.

Step2: Match with the Given Options

Option (3) is edges of tectonic plates, which is the correct answer.

Answer:

(1) \(C
ightarrow B
ightarrow D
ightarrow A\)

Question 4