2004 Indian Ocean earthquake and tsunami and a network of sensors is needed to detect it. Setting up the communications infrastructure to issue timely warnings is an even bigger problem, particularly in a relatively impoverished part of the world. Tsunamis are more frequent in the Pacific Ocean than in other oceans because of earthquakes in the "Ring of Fire". Although the extreme western edge of the Ring of Fire extends into the Indian Ocean (the point where the earthquake struck), no warning system exists in that ocean. Tsunamis there are relatively rare despite earthquakes being relatively frequent in Indonesia. The last major tsunami was caused by
Ocean acidification in the Arctic Ocean is thought that because of this, additional stressors such as ocean acidification, will cause ocean acidification effects on marine organisms to appear first in the Arctic. There exists a significant variation in the sensitivity of marine organisms to increased ocean acidification. Calcifying organisms generally exhibit larger negative responses from ocean acidification than non‐calcifying organisms across numerous response variables, with the exception of crustaceans, which calcify but were not negatively affected. The acidification of the Arctic ocean will impact these marine calcifiers in several different ways. The uptake of CO₂ by seawater increases the concentration of hydrogen ions, which lowers pH