Declinations and earthquakes
SUNDAY JULY 01, 2012
Declination is the name given to the latitude (of the earth) position of the moon as it crosses between hemispheres in the course of a 27.3 day month. The moon does this N to S trek because of the 23deg tilt of the earth. Viewed from earth it is the way the moon's transitting arc ascends daily, each day a little higher until a highest point is reached for the month, followed by a descending arc for another 14 days to reach a lowest arc above the horizon..
Viewed from space the moon would be seen going around a tilted earth at the level of the equator, crossing the equator twice in a month, once when entering over the N hemisphere, and 14 days later when heading towards the S hemisphere again.
Because of declination large volumes of water are carried between the hemispheres, causing the currents. These currents influence surface winds and cause waves. The winds and waves influence the formation of pressure zones, as high pressure always tends to transition to low pressure. Change of hemispheres by the moon brings change in barometric pressures.
There is also an inclination of the moon, which is a hopping from side to side of the ecliptic, or plane of rotation around the earth. The node is when the moon crosses the middle of this plane. Eclipses can only occur at times of full or new moons on the node positions.
Over 18.5 years a cycle from maximum to minimum declination point and back again is reached. The node precesses through this period. This has a gross effect on barometric pressures.
The way it works is that when the north node of the moon retrogrades, the minimum declination is reached at 18deg09, and for the southern hemisphere the moon exerts its maximum influence on barometric pressure and on high average of precipitation. This point will be reached in September 2015.
Storms also track following more southerly courses after the midpoint declination of 23deg27, which was reached in June 2011. We are therefore in a period that should be getting overall wetter over the next two years, than was the situation from 2006, which was the last maximum declination, through to 2010.
Stone structures such as Stonehenge were calculators for declinations. Amongst other functions it seems declinations and eclipses were a preoccupation with ancient stone -buiding cultures. The stones are all aligned to the maximum and minimum moon positions, with marker stones on distant hills visible from viewing patforms in the centre of the circles. The stone circles would still work today, but few seem to realise how well they are all aligned to the moon.
These variations in maximum and minimum declination have been found to affect the movements of ocean surface tides all over the world, resulting in rhythmic climatic cycles. The greatest tidal variation for the kingtide times is around the minimum declination. That means higher kingtides and lower low tides. It also means lesser chances of earthquakes, probably because an extra low seatide is because of a higher than normal land tide, which indicates that stress is already being released.
For that reason the minimum to midpoint years of 1995-2000, moon in ascending node, saw a stability in earthquake numbers. But between 2000-2005 (midpt-max declination), when the moon was in descending node, the number of earthquakes increased. For example, from 2004 - 08 (April-September), 33 out of 34 large earthquakes were close to maximum and mid lunar declinations.These were the years coming up to maximum declination (2006), and smaller tidal variation.
Perigee is the name given to the cycle whereby the moon comes closer and further away through 27.5 days. Perigee is the closest point, and brings kingtide timing. Perigee position with respect to the max/min declination cycle also plays a part in earthquake numbers, and 1990 (perigee at N dec), 1995(perigee at S dec), 1999(perigee at N dec), 2004(perigee at S dec) and 2008 (perigee at N dec) saw increased numbers of large earthquakes in these years. This is because large earthquakes are a function of lateral pull from the moon. More southern hemisphere earthquakes are therefore the N declinations and vice versa.
The position of the Moon with respect to the axis of rotation of the earth plays an important role in triggering of earthquakes. The earth rotates at a speed of 1669 km/h in west-east direction. The earth revolves around the sun at a speed of about 107000 km/h. The moon moves in a counterclockwise direction with an average orbital speed of about 3600 km/h. The sun-earth-moon system is very complex and it seems difficult to imagine that a stable equilibrium will exist all the time with these high speeds.
The occurrence of large earthquakes near maximum and mid-declination years (1987-92, 2006-11) shows that interior of the earth is disturbed due to rotation of the earth when the moon crosses these positions. The last midpoint year was 2011. It seems that when the earth rotates on its own axis with an inclination of 23.5deg the earth-moon interaction seems to affect the earth's angular momentum, and that activates the molten lava to push the mantle, and numbers of smaller earthquakes increase.
Probably the linear motion of the earth has some effect. The position of the lunar perigees also significantly affects the number and magnitude of earthquakes. The moon's perigee effect is usually 30% greater at perigee than at apogee. Correspondingly therefore, the humidity should also be 30% greater at perigee than at apogee. And when tides are higher, barometric pressures should also increase in variation during minimum declinations.
This means we are approaching years of higher tides and barometric pressures coming up to 2015, the next minimum declination year. It should be accompanied by a reduction in earthquake numbers. Around maximum declinations barometric pressures are averagely lower. The higher declination years are drier, as we experienced in 2006 and will again in 2025. The lower declination years such as 1997 offered higher rainfall figures and higher numbers of days with recordable rain, and will again in 2015.
Midpoint to minimum has been 2011-2015, and has seen a decline in earthquakes after 2011. Around and after 2015 the situation changes, on the slope towards maximum declination, and should see a return to larger earthquake numbers again.
© Ken Ring 2012