The largest magnitude quakes are nearly on the same longitude.

Map (click here)

M6.9 - 96km 

SSE of Raoul Island, New Zealand

2014-06-23 19:19:16 UTC30.118°S, 177.670°W

Less than a degree difference. There has to be an underwater structure. 

Maybe not. It's just the plate. The depths don't even indicate a relationship. It is the trenches along the Pacific Plate. The plate is the only relationship between the two locations.

M7.9 - 24km SE of Little Sitkin Island, Alaska2014-06-23 20:53:09 UTC51.797°N 178.760°E depth=107.5km (66.8mi)
June 23, 2014By Brandon Mercer

ALEUTIAN ISLANDS (CBS SF) — A massive 7.9 (click here) revised magnitude earthquake off Alaska’s remote Aleutian Islands has triggered a regional tsunami, with reports of water already leaving some harbors including Adak Harbor, as the waves begin to come in.

California’s coastline is highlighted in the National Weather Service tsunami energy propagation map, however, no warning has been issued for the West Coast.

Seismologist David Oppenheimer stationed in Menlo Park said, “The message is simple: wait for the tsunami warning to say what’s going on, if there is a warning, NOAA will update their advisory.”

He added, “There’s report of a tsunami in Alaska, but it’s small. Had the earthquake been shallow, there could have been big waves and more displacement. NOAA is watching for tide gauges.”

With the small amount of sea floor movement, Oppenheimer was clear, “There’s nothing to be concerned about on the California coast....”