Sunday, July 29, 2018

Large 6.4 Earthquake strikes on Lombok approximately 80 KM from Bali


We were all still in bed on a lazy Sunday morning on July 29 in Bali when at approximately 6:47 a huge earthquake of 6.4 magnitude struck.

It was strong enough to wake up my son which is a miracle.

The earthquake struck approximately 80 km or 40 miles from the eastern tip of Bali on the island of Lombok.


We have a drill in place to get my family and to evacuate to higher ground because we are right on the beach and there's always a minor chance of a tsunami. As always better safe than sorry.

One thing that bothers me about this earthquake is it was extremely strong and hit in a very poor rural area of northern Lombok. I won't be surprised if over the next 24 to 48 hours many reports of fully collapsed homes, injuries and possibly even deaths are associated with this quake. I pray that I'm wrong.

One thing I feel relatively right about is the fact that this was triggered by the unusual activity the last few days of extremely high swells associated with King tides and possibly even the longest Lunar ellipse coupled with  a once-in-a-lifetime alignment of the Earth, Sun, Moon and Mars yesterday morning.

One of my past blogs went viral with over 150,000 readers including magazines asking to reprint several years ago in a similar situation after we had large tides followed by a huge offshore earthquake on June 15, 2016 .

 At the time I wrote that there’s probably an association between uncommonly high tides and earthquakes

At this point it appears there is no threat of a Tsunami.

 I'm still waiting for reports from damage, injuries or even deaths on Lombok. Stay Tuned.
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Read Further my Past Blogs on this Subject.

As a former yacht Capt. with my own yacht and charter service for five years in Bali when I first arrived here, I have years of experience and knowledge of Bali's waters and I want to warn you that they can be some of the most dangerous in the world, if you don't understand what's going on.

Every day the tide changes twice a day and vast amounts of water flow up and down the Bandung Strait between Bali and Lombok.

As the huge amounts of water get squeezed between Lombok and Bali  it increases the velocity making for some of the strongest currents in the world.




When you think of the quantity of water moving and then you add another 60 or 70 cm height it is easy to understand why when these tides are exceptionally high they can put pressure on the tectonic plates that surround Bali and Indonesia to trigger massive earthquakes.




I remember sailing off of Lombok with the engine on full power and not moving as the tide shifted and I knew that my hull speed was at least 8 knt. or perhaps even more with the engine and no current.


Posted June 11th 2016:
 Last Thursday at 12:13 a 6.2 earthquake went off 300 km off of Bali and shook my office building violently.

I immediately called my maid and had my sons evacuated to higher ground from our beachfront residence in case there was a tsunami. 

I learned after 10 years of being a captain on a yacht it is always "Better safe than sorry". 

Turns out there was no tsunami, thank God. 

Later that day it dawned on me and I shared this with my 12 yr old son that we had a a King tide or spring tide at approximately the same time that the earthquake went off. I wondered, are they related?

Many people experienced flooding on both coasts of Bali during that time. 

At approximate the same time Bali experienced a  2.3 meter tide that hit all the coasts.


Using my several years of engineering education and 40 years of sailing I reasoned that large volumes of water moving from one part of the ocean to another part of the ocean exerts extra pressure on various areas of the Technonic plates that surround Bali and other places around the world.

I am now pretty convinced Spring tides or tides substantially higher than normal can cause earthquakes in areas that have active Technonic plates. 
I googled it and sure enough in black-and-white my theory could be right based on a study conducted utilizing a Harvard University database.

High Tides Trigger Earthquakes

By Sarah Davidson | October 26, 2004 05:00am ET





Map of the major plates of Earth.Credit: USGS


The weight added by water at high tide can trigger movement close to land in earthquake faults that are already active, according to new global analysis.



"The importance of this work is to understand what stresses are needed to trigger a fault and this is one step of many that are needed to do that," Elizabeth Cochran, the lead author of the study told LiveScience. The study looked at data, taken from a Harvard database, of 2,000 earthquakes with magnitudes of 5.5 or higher in places where one piece of Earth's crust dives beneath another.

The surface of the Earth is not unbroken; rather it is divided into several large plates that move around on top of the planet. Wherever these plates come together there are faults. When a piece of ocean crust runs into a piece of continental crust, it is pushed beneath the lighter continent. Pressure builds. The release of pressure along a fault is what makes earthquakes.

The faults examined for the study, detailed recently in the online version of the journal Science, were near the surface and not far offshore, so that tides provide an increase and decrease in pressure due to the amount of water covering them.

"Large tides have a significant effect in triggering earthquakes," Cochran said. "The earthquakes would have happened anyway, but they can be pushed sooner or later by the stress fluctuations of the tides."

Because of gravity, the side of the Earth closest to the moon has a bulge of water. As our planet rotates the water on the opposite side, furthest from the gravity of the moon, essentially attempts to escape Earth's surface and creates a second high tide.

Another example of this force, called inertia, is how you feel when a car speeds around a corner. Although the car is going in a different direction, you are thrown against the door because your body is trying to continue in the same direction as before. On the remaining two sides, the forces of gravity and inertia even out and the water is neither trying to escape nor being pulled toward the moon, resulting in low tides.

A computer program developed by co-researcher Professor Sachiko Tanaka models how the Earth responds to the Moon and the addition of water weight, as well as a model of the ocean floor.

"The program is an important part and why only in the last few years have we been able to do this (research)," Cochran said. "This is the first study that has been able to take into account the amplitude of the tides."

Cochran said larger tides have a higher chance of triggering an earthquake on an active shallow fault near land, compared with regions where tides are less severe.

- See more at: http://www.livescience.com/41-high-tides-trigger-earthquakes.html#sthash.leXmc2NB.dpuf


Updates : 

June 11, 2016 :

Did Rob ( King) tides cause earthquake off Bali last week? 


June 17, 2016 :

June 17, 2016 :

June 20, 2016 :

June 21, 2016 :

June 21, 2016: 

Sept 14, 2016: 

Sept 26, 2016: 

Sept 28, 2016: 

Nov. 14th, 2016:

Nov. 15th, 2016:

Nov. 19th, 2016:


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