Have you ever wondered why there are different colors of beaches in Hawaii?

a. During a week-long trip to the Big Island of Hawaii, EPS concentrators were able to study different types of sand (and enjoy the waves as well). Students visited black sand beaches like Punalu’u, Waipi'o Valley, and Polulu; and the white sand beaches of Spencer Beach and Mau’umae Beach. Hawaii also hosts a green sand beach composed of olivine crystals derived from basaltic lava rocks.

b. 360 Video: 35—Punalu’u Black Sand Beach The island of Hawaii was built up from the ocean floor by mostly basaltic lava flows. Basalt is a dark black rock, which is weathered and deposited as black sand beaches. Basalt has low silica content, so there are no white silica sand beaches in Hawaii (like most of those you’d find on the coast of the continent). Instead, white sand in Hawaii is derived from bits of coral reefs. Punalu’u is also known for the sea turtles (honu) often seen on the beach.

c. 360 Video: 85; 360 Photo 84—Polulu Valley Beach Like Punalu’u, the Polulu Valley beach is composed of weathered bits of basaltic rock. The Polulu Valley, however, is on the very wet eastern side of the island, where increased rates of erosion have formed the steep valley walls that surround the beach.

EPS students stroll along the Punalu’u Black Sand beach on the south side of Hawaii.Figure 1: EPS students stroll along the Punalu’u Black Sand beach on the south side of Hawaii

Leore Lavin, Matt Luongo, and Maya Chung enjoy multiple angles of the Polulu Valley black sand beach.Figure 2: Leore Lavin, Matt Luongo, and Maya Chung enjoy multiple angles of the Polulu Valley black sand beach

EPS concentrators pose for a group shot at Spencer Beach Park during the 2016 undergraduate field trip to Hawaii.Figure 3: EPS concentrators pose for a group shot at Spencer Beach Park during the 2016 undergraduate field trip to Hawaii.

EPS concentrators make their mark on the Polulu Valley black sand beach.Figure 4: EPS concentrators make their mark on the Polulu Valley black sand beach.

The view of EPS concentrators from above the Polulu Valley beach.

Figure 5: The view of EPS concentrators from above the Polulu Valley beach

See also: Hawaii 2016