Background: Submarine volcanoes are common features of the ocean floor. In shallow water, active volcanoes disclose their presence by blasting steam and rocky debris high above the ocean's surface. In the ocean's deep, the tremendous weight of the water above prevents the explosive release of steam and gases; however, they can be detected by hydrophones and discoloration of water because of volcanic gases. Pillow lava is a common eruptive product of submarine volcanoes and is characterized by thick sequences of discontinuous pillow-shaped masses which form under water. Even large submarine eruptions may not disturb the ocean surface due to the rapid cooling effect and increased buoyancy of water (as compared to air) which often causes volcanic vents to form steep pillars on the ocean floor. Hydrothermal vents are common near these volcanoes, and some support peculiar ecosystems based on dissolved minerals. Over time, the formations created by submarine volcanoes may become so large that they break the ocean surface as new islands or floating pumice rafts.

Situation: Planet X had two large oceans. Ice ocean had few submarine volcanoes, while Tropical ocean had thousands of active volcanoes on the ocean floor.

Question: Which ocean had more volcanoes blasting steam high above its surface?
Answer: Tropical

Situation: Planet X had two large oceans. Ice ocean had few submarine volcanoes, while Tropical ocean had thousands of active volcanoes on the ocean floor.

Question: Which ocean had fewer volcanoes blasting steam high above its surface?
Answer: Ice

Situation: Planet X had two large oceans. Ice ocean had few submarine volcanoes, while Tropical ocean had thousands of active volcanoes on the ocean floor.

Question: Which ocean had fewer volcanoes blasting rocky debris high above its surface?
Answer: Ice

Situation: Planet X had two large oceans. Ice ocean had few submarine volcanoes, while Tropical ocean had thousands of active volcanoes on the ocean floor.

Question: Which ocean had more volcanoes blasting rocky debris high above its surface?
Answer: Tropical

Situation: Planet X had two large oceans. Ice ocean had few submarine volcanoes, while Tropical ocean had thousands of active volcanoes on the ocean floor.

Question: Which ocean had more hydrophones on the ocean floor?
Answer: Tropical

Situation: Planet X had two large oceans. Ice ocean had few submarine volcanoes, while Tropical ocean had thousands of active volcanoes on the ocean floor.

Question: Which ocean had fewer hydrophones on the ocean floor?
Answer: Ice

Situation: Planet X had two large oceans. Ice ocean had few submarine volcanoes, while Tropical ocean had thousands of active volcanoes on the ocean floor.

Question: Which ocean showed less discoloration of water because of volcanic gases?
Answer: Ice

Situation: Planet X had two large oceans. Ice ocean had few submarine volcanoes, while Tropical ocean had thousands of active volcanoes on the ocean floor.

Question: Which ocean showed more discoloration of water because of volcanic gases?
Answer: Tropical

Situation: Planet X had two large oceans. Ice ocean had few submarine volcanoes, while Tropical ocean had thousands of active volcanoes on the ocean floor.

Question: Which ocean had more pillow lava formations?
Answer: Tropical

Situation: Planet X had two large oceans. Ice ocean had few submarine volcanoes, while Tropical ocean had thousands of active volcanoes on the ocean floor.

Question: Which ocean had fewer pillow lava formations?
Answer: Ice