|Fig. 1 King Tides on |
Some areas are talking about "king tides" this week ("King Tides Take Over Coastal Towns Just in Time for Thanksgiving", Weather Channel).
Any subject that deals with activities on coastlines around the world is not complete in the Anthropocene Epoch without some discussion of sea level rise (SLR), as one way of envisioning the near future in real time:
To avoid confusion, it’s important to know that king tides aren’t part of climate change; they are a natural part of tidal cycles but they do give us a sneak preview of what higher sea levels could look like. The actual height reached by a king tide will depend on the local weather and ocean conditions on the day.(King Tides Project). The subject matter today concerns why SLR is turning regular king tides into more serious flooding events (Fig. 1).
It is possible that by 2060 to 2070 [an underestimate IMO - Dredd] we could experience tides of the magnitude of king tide events every month due to sea level rise induced by climate change.
This project aims to promote awareness of the impacts of sea level rise, and help to visualize coastal areas that are vulnerable to tidal inundation which can be monitored over time.
Note especially, though, that the addition of SLR causes flooding at different rates in different areas.
But before we launch into that aspect of the subject, let's refresh our memory about the natural aspect of king tides:
When a new moon or full moon align with Earth and the sun, the gravitational pull on Earth's oceans causes strange things [to] happen. Water creeps up(Weather Channel). That is one "type" of gravity which impacts upon sea level and tides, but there are other types of gravity that do so even more (The Gravity of Sea Level Change).
along the shore and even into coastal towns – some of the highest tides of the year.
Fig. 2 Newton's Law of Gravity
"The king tides arise from a combination of two factors. First, this is the time of year, known as perigee, when the moon is closest to Earth, exhibiting the strongest gravitational pull," weather.com meteorologist Jonathan Erdman says. "Secondly, around the full and new moon each month, the Earth, moon and sun are roughly aligned, and that increases the gravitational tug on the tides. Then, if either a storm is approaching or simply onshore winds are persisting, water will pile up along the shore, leading to further water rise."
|Fig. 3 This king tide never happened to Grandpa|
That factor is distance (Fig. 2).
When communities are close to large glacier fields, or close to ice sheets, then as those icy areas melt, the gravity decreases in Newton proportion to the loss of ice mass (Proof of Concept - 3).
|Fig. 4 San Francisco history|
Focusing on a "flood" event, using "king tide" to describe that event, is dishonest when we know that the area did not flood at king tides of the past (Bay Area may see flooding this week thanks to strong king tides, This week’s king tides bring danger of flooding, glimpse of future).
|Fig. 5 Future Projection|
I have discussed the constitutional right to lie (It Takes A Culture To Raise A Compulsive Liar).
But, that right vanishes when it causes harm, and when it causes fraud (Agnotology: The Surge - 18).
The "Hundred Years War" now under way (Watch The Ice Shelves) is not composed of king tide armies, rather, it is composed of the impact that our fossil fuel use has caused.
I am talking about global warming induced SLR (Greenland & Antarctica Invade The United States, 2, 3, 4; The Extinction of Chesapeake Bay Islands, The Extinction of Houston, The Extinction of Providence).
The king tide is hitting the "bay area" of San Francisco this week, so I added two graphs which show actual tide gauge station historical sea level change (SLC) data, as well as the actual historical pattern of global mean sea level (GMSL) and global mean surface temperature (GMST) data (Fig. 4).
There is little doubt that local sea level there is on the rise, with GMSL and GMST generally on the rise elsewhere.
Thus, the king tides of today are higher than those of our grandfathers.
What about the king tides of the future?
Check out Fig. 5 for some ideas.
The next post is this series is here.
We can all contribute data or start a chapter: