The Blob (Pacific Ocean) the surface waters of the mid-latitude Pacific Ocean flipping from a cold phase to a warm phase in a cycle known as the Pacific decadal oscillation (PDO). This poorly-understood change happens at irregular intervals of years or decades. During a warm phase, the west Pacific becomes cooler and part of the eastern ocean warms; during the cool phase, these changes reverse. Scientists believe a cold phase started in the late 1990s and the arrival of the Blob may be the start of the next warm phase. The PDO phases may also be related to the likelihood of El Nino events.
Geology of the Pacific Ocean existed. In a remote region of the central Pacific Ocean, at the southeastern section of the Gilbert Islands, a major swarm of intraplate earthquakes occurred between December 1981 and March 1983, with no prior seismicity having been reported in this region previously. Another swarm was detected on the Queen Charlotte Islands fracture zone in August–September 1967. The Pacific Ocean contains several long seamount chains, formed by hotspot volcanism. These include the Hawaiian–Emperor seamount chain, the Tasmantid Seamount Chain, the Lord Howe Seamount Chain and the Louisville Ridge. Geology of the Pacific Ocean The Pacific Ocean evolved in the Mesozoic from