Recently, the National Aeronautics and Space Administration (NASA) has shed light on an intriguing lunar phenomenon, known as the Moon’s Wobble. This cyclical shift in the Moon’s orbit has been studied for centuries and may pose future concerns.
The Wobble refers to a subtle variation in the moon’s velocity as it orbits the Earth. This shift causes our perspective of the “light side” of the moon to adjust slightly. First documented in 1728, this ongoing wobble requires 18.6 years to complete its cycle. Intriguously, the wobble serves as a backdrop to rising sea levels on Earth.
Understanding the Impact of the Moon’s Wobble
The moon’s gravitational pull is directly impacted by the wobble, leading to indirect effects on Earth’s tides. Each cycle can both amplify and suppress Earth’s tides. For half of the 18.6-year cycle, the high tides are lower than normal and low tides are higher than the average. This reversal in the latter period is named the tide-amplifying phase of the moon.
Forthcoming Concerns Related to the Lunar Cycle
The lunar cycle is anticipated to change around the mid-2030s. This next phase will lead to greater tidal amplification. With rising sea levels, the enhanced high tides add to the risk of serious flooding in all global coastal areas. As this scenario presents an elevated baseline, it decreases the size of weather events required to cause floods.
These heightened tidal floods, also known as nuisance or sunny day floods, may cluster and persist for several months or potentially longer periods. The surge correlates with the relative positions of the Moon, Earth, and Sun.
A Primer on Tides
Tides refer to alternating rises and falls in oceanic waters. Caused by the combined gravitational forces of the Sun and Moon on Earth, along with Earth’s rotation, tides vary in their characteristics.
Types of Tides
Spring Tide: Occurring during full and new moon phases when the Sun, Moon, and Earth align, resulting in higher than average tides.
Neap Tide: Occurring during the first and last quarters of the Moon phase, yielding lower than average tides due to the gravitational pull from the Sun and Earth pulling ocean waters in opposite directions.
Tidal Changes and Their Stages
High tide is observed when a tidal crest arrives on shore, elevating local sea levels. A low tide occurs when the trough arrives, thereby lowering local sea levels. A flood tide is an incoming tide between low tide and high tide. Ebb tide relates to a falling or outgoing tide between high tide and low tide. The vertical distance between high tide and low tide is referred to as the tidal range.
The Impact of Tides on Coastal Life
Tides substantially affect marine life, influencing the reproductive cycles of fish and marine plants. They assist navigation by raising water levels near shores, enabling easier harbor access for ships. Tides also stir ocean waters, helping maintain habitable climates and temperature balance across planets. Additionally, the rapid water movement during tidal inflow and outflow presents renewable energy opportunities for coastal communities.
