The tropical Pacific Ocean isn't flat like a pond. Instead,it regularly has a tall side and a low side. Natural cycles such as El Niño and La Niña events cause this sea level seesaw to tip back and forth, with the ocean near Asia on one end and the ocean near the Americas on the other. But over the final 30 years, or the seesaw's wobbles have been more extreme,causing variations in sea levels up to three times higher than those observed in the preceding 30 years. Why might this be?
Source: phys.org