Recent (March 2025) headlines blared out a warning:
“Hawaii is sinking faster than we thought!” (Wx Channel, 3/26/25), “Hawaii sinking, in ocean…”BGR 3/31/25Josh Hawkins, ‘Hawaii is sinking at an alarming rate” 4/2/25 WKRC TV 12,
We have been bombarded recently by stories of a sinking Hawaii. Most of it is the result of a legitimate study by the University of Hawaii at Manoa which found that parts of Oahu the chain’s most populated island and capital at Honolulu is indeed sinking faster than expected. The stories have a seed of truth, but as most things the truth is more complex.
The headlines caught my attention because it does underscore a recent trend in media exaggerations concerning environment and climate, and it helps make an other important point. Our general misperceptions concerning change.
The Earth is a dynamic planet in which change is normal. Change is constant. The Greek philosopher Heraclitus of Ephesus (5th BC) said: “One can not step into the same river twice”. Change is the constant. The static state does not exist..everything is undergoing constant change. …so read on. It’s perfectly normal for Hawaii to be sinking…no need to get aroused about it.
The Earth is almost 4.5 billion years old. That averages out to about 56 million human lifetimes (of 80 yrs each). No human has a perspective long enough to discern changes that occur very slowly. As a result, in the fleeting eye blink of “human time”, minuscule tiny part of “Earth time” to us everything is standing still. The “eye blink” length of human time leaves us erroneously convinced we live in a static unchanging world.
For all of us, Africa is that big continent three thousand away miles across the Atlantic Ocean and has always been there. We are certain that the Atlantic borders our east coast and its waves beat on our shores from the beginning of time; and icy glaciers occur only in the Arctic and Antarctic. Our short term lives do not permit a perspective that would reveal to us that Africa, North and South America were once part of one big continent and that there was no Atlantic Ocean between. Or that the Atlantic is a “new” ocean which was not in existence 200 million years ago. Our short lives do not permit us to “see” our North American continent slowly moving westward and 90 million years ago, as tectonic plates crumpled up the Rockies and raised the Colorado Plateau in Arizona, to steepen the slope of Colorado River making it flow so fast as to permit it to carve its way a whole mile down into the rising colorful and stratified rocks it flows over in the Grand Canyon. Change change change keeps going on!
Our failure to see into the past leads us to the erroneous conclusion that there is something very wrong with our drastically changing climate because it is changing. Like everything else, in our short term world…Earth is supposed to remain just as it was in 1960 when we were youngsters. For us, any evidence of “change’ is unexpected and a threat to our “safe” unchanging imagined “static Earth”.
But the 4.5 billion year old Earth is in constant flux and change. Where I sit here today, a mere 17,000 years ago this hilltop was covered by a vast two thousand foot thick sheet of ice which covered almost one-third of North America. On its surface there were no trees, no hills, no abundant life..only ice and snow—- just like what we see in central Greenland today.
So the blaring headlines in our newspapers…”Hawaii’ is sinking”, should not come as a shock.The Earth is in constant change…just as we expected.
Hawaii is a chain of eight islands, (From southeast to northwest the major islands of the chain or archipelago are Hawaii, Maui, Lanai, Molokai, Oahu, Kauai ) which stretch to the northwest first as islands and then beyond Kauai as undersea sea mounts for about 1600 miles.
The islands sit on the Earth’s crust which is about 6 miles (10 km) thick under the oceans (but 7 x as much, or about 42 +/- miles thick where continents occur). Continents and ocean crust slide around on the underlying soft upper mantle (or astenosphere) which is about 60 miles thick (The astenosphere is the top part of the almost 2,000 miles thick Earth Mantle).
The Earth’s crust is divided up into about eight (8) tectonic plates which fit together like a spherical jig saw puzzle. One of the largest of these is the Pacific Tectonic Plate. The Hawaiian chain sits on the Pacific plate which—like all things on the Earth is in constant motion.
The Pacific plate is moving at a rate of about 97mm (9.7cm or @3.8 inches) toward the northwest, sliding toward Kamchatka, Russia and the Japan Kurile Trench. There, it sinks into the soft mantle (it undergoes subduction) sliding below another tectonic plate, the Okhotsk Plate. As it descends into the mantle’s asthenosphere, it melts and is recycled.
Located about 2000 miles (3600km) from the US west coast, Hawaii (the island) is the largest, and most southerly island of the Hawaiian chain. At its present-day location Hawaii sits atop a hot plume of magma which has melted up though through the 6 miles (10km) of ocean crust to pour its low silica, very fluid, hot (1000ºC) basaltic lava out onto the surface though a vent at the peak of actively erupting Mona Loa volcano. Mona Loa epruptredf in 1984 spreading new lava flows over almost 20 square miles of Hawaii near the summit. Mona Loa erupted last for 16 days in November to December 2022. The flow has built up a low-angle volcanic mound (shield cone) that rises over thirteen thousand feet (13,000 ft) above sea level (@4,000m).
Kilauea is located (109,000ft/5280ft=/~21miles south east from Mona Loa. Kilauea is presently the most active growing volcano and is probably located over the Hawaiian hot spot. Kilauea is presently erupting (March 3, 2025) the summit crater has had 16 episodes since December 23, 2024. It is presently the most active volcano on Hawaii.
In fact, the headlines are false…Hawaii island is not sinking at all…the big island of Hawaii and the earth crust upon which it sits is actually a bit higher than the other islands in the chain. And the cause of this difference elevation is the driving force of a massive hot plume of dense basaltic molten rock which, as it rises to the surface generates pressure upward. (Newton’s 2nd Law, F=ma ) That upward force is driven by the acceleration of the very dense (mass) of the plume of rising molten rock pushing the crust upward. Since the plume sits directly below the island, it actually creates a minor bulge in the six mile thick crust causing Hawaii to rise…not sink.
Hawaii Island and the rest of the islands in the archipelago are in fact the result of the activity of this one “hot spot”. The entire triangular shaped island of Hawaii (about 75 miles wide and about 150 miles long) is the result of the outpouring of lava from this one permanent hot spot in the mantle located about 6 miles below the sea floor crust. (Note. there are many “hot spot” plumes arising from the mantle worldwide..some well known ones occur in: Siberia Russia (Russian Basalt Flows) Afar Triangle in Africa, Yellowstone National Park, and Iceland.)
Mona Kea the other shield cone volcano on Hawaii is an “inactive”volcano located about 25 miles (44km) from presently erupting 13,000 ft high Mona Loa where the hot spot plume is now located and which feeds molten lava into the volcano vent. See recent reports of lava flows
Interestingly the position of the Hawaiian hot spot arising from the mantle has remained unchanged for millions of years….but the earth crust above it is in constant motion. The earth crust is made up of a moving puzzle board of eight major plates which slide over the Earth’s surface.
As the Pacific Plate slides over the hot spot plume it bulges upward hot magma erupts on the sea floor and slowly builds up to create a volcanic island, but as the plate moves northwest the island it created slowly descends down the earth crust “bulge point” and sinks. Eventually the island moves so far from the hotspot “rise” or bulge point that is sinks below the waves becoming a sea mount. One must also take into account that over the millennia the islands undergo chemical and mechanical weathering, erosion, mass wasting, and wave action which also aid in the process of decline. Fantastic!
Thus the islands to the northwest of the big island Hawaii are, as the move away from the hotspot bulge, all slowly sinking below the waves. With the exception of Hawaii island all the others are actually sinking. But the rate is glacially slow only about 0.6 mm per year! At that rate it would take ten years to sink the thickness of a “grout joint” between the tiles in the bathroom floor.
From southeast to northwest the major islands of the chain get older as they move northwest toward Japan on the Pacific tectonic Plate moving along at 97mm per year (9.7cm or @ 3.8 inches). The big island Hawaii is the youngest and biggest (having not suffered any erosion or sinking as yet) and probably formed some 500,000 years ago. Maui farther NW is 1.3 million years old and has been moving in this direction and sinking at about 0.6 mm per year as it moves northwest at a rate of almost four inches per year; Lanai (1.3 myo), Molokai (1.8 myo), and Oahu (3.4 myo), Kauai is style oldest and at 4.9 million years old having moved from the hotspot almost 5 million years ago and experience subsidence for all that time too.
For Kauai which has been moving for about 5,000,000 years at almost 4 inches per year, it should have moved about (4in x 5million yrs = 20,000,000 inches. (20,000,000 /12in =1,666,666.667 ft /5280ft ~315 miles
Present distance from center of Kauai to Hawaii measured on Google Earth~about 309 miles
Suggesting that over the last 5 million years the rate of movement may have been relatively steady.
Conclusions:
As Heraclitus said more than 2500 years ago…”there is no place on earth where you can step twice in the same place”…if you could find that place!
Except for Hawaii all the other islands are sinking, but very slowly at about 0.6 mm per year.
The big island Hawaii is not sinking.
Oahu the most populated island is sinking—in some places—as much as 25 mm per year, or about one inch per year. These rates of sinking (0.6 mm occur along the south shore where low lying marsh land have been filled. Compaction of the fill land by recent construction (?) may be causing the higher rate of sinking in those places.
Note: I did not have access to the University of Hawaii study. This generalized account is not meant to add too or criticize that report. I am critical of the hyperbole, exaggeration, misleading headlines and disinformation of some of our media…as I here use only at the generally known geological data about the Hawaiian archipelago to critique the popular media reports.
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