Loihi is an active volcano located south of Kilauea (see Figure 2). Loihi’s peak is still below sea level, but it is actively growing taller. If the hot spot theory is correct, how would you expect the map of the Hawaiian Islands to change in next few million years? **Purpose:** Use the track of the Hawaiian hot spot to determine the speed and direction of motion of the Pacific plate.**Hot Spots**According to plate tectonic theory, hot spots are mantle plumes—large columns of hot, rising mantle rock that originate in the lower mantle (Figure 1). Decompression of the rising mantle rock causes partial melting. The resulting basaltic magma then rises through the lithosphere above and erupts to form a basaltic volcano. The locations of hot spots remain fixed relative to the moving lithospheric plates above. The result is a "hot spot track"—a chain of volcanoes all of which are extinct except for the one on the end of the chain that is still over the hot spot.**The Hawaiian Hot Spot**The Hawaiian Islands are a chain of basaltic shield volcanoes. The "big island" of Hawaii is made of several overlapping volcanoes, with Kilauea being the most active. The volcanoes on the smaller islands to the northwest of the big island are extinct. According to plate tectonic theory, the big island is currently located above a hot spot. Figure 2 is a map of the Hawaiian Islands. Read the caption for Figure 2 and study the map before moving on.**The Hawaiian-Emperor Seamount Chain**The Hawaiian Islands lie at the southeast end of a much longer volcanic chain—the Hawaii-Emperor Seamount chain (Figure 3). Seamounts are extinct basaltic volcanoes whose peaks are now submerged below sea level.The Hawaii-Emperor Seamount chain is interpreted as a hot spot track that is nearly 6,000 km long. The oldest of the Emperor Seamounts (Meiji Seamount—about 70 Ma) is located at the northernmost end of the chain. This end of the chain is actively being subducted beneath the Aleutian trench (see Figure 3). The Hawaiian-Emperor chain used to be longer, but the earliest parts of the chain have already been subducted and recycled back into the mantle. Read the caption for Figure 3 and study the map before moving on.**Figure 1 Explanation**Figure 1 shows a typical hot spot (mantle plume) with large arrows indicating the direction of motion of the lithospheric plate. The diagram depicts the lithosphere, oceanic crust, and the rising mantle plume that leads to decompression melting, fueling the formation of volcanic islands like Hawaii. **Map of the Hawaiian Islands**The map illustrates the Hawaiian Islands and the locations of basalt lava samples. The islands included are Niihau, Kauai, Oahu, Molokai, Lanai, Kahoolawe, Maui, and Hawaii. Each island is marked with points to indicate where basalt lava samples have been collected. The numbers in parentheses next to the island names represent the ages of the oldest dated rocks in millions of years, as determined by radiometric dating.- **Niihau:** 4.89 million years- **Kauai:** 5.1 million years- **Oahu:** 3.7 million years- **Molokai:** 1.9 million years- **Lanai:** 1.28 million years- **Kahoolawe:** 1.32 million years- **Maui:** 1.03 million years (0.75 million years for a specific sample)- **Hawaii:** Kohala (0.43 million years), Mauna Kea (0.375 million years)The map also highlights active and historically active volcanic sites on Hawaii, such as Mauna Loa, Kilauea, and Loihi.A scale is provided, showing distances in kilometers, with a maximum of 200 km. The map is oriented with north at the top as indicated by the north arrow.This information aids in understanding the geological activity and age distribution of the islands.

Hot spot is an area of volcanic eruptions with high heat flow above a rising mantle plume. These…

Answered: Loihi is an active volcano located…

Applications and Investigations in Earth Science (9th Edition)

9th Edition

ISBN:9780134746241

Author:Edward J. Tarbuck, Frederick K. Lutgens, Dennis G. Tasa

Publisher:Edward J. Tarbuck, Frederick K. Lutgens, Dennis G. Tasa

Chapter1: The Study Of Minerals

Section: Chapter Questions

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Loihi is an active volcano located south of Kilauea (see Figure 2). Loihi’s peak is still below sea level, but it is actively growing taller. If the hot spot theory is correct, how would you expect the map of the Hawaiian Islands to change in next few million years?