The equatorial bulge means that people standing at sea level near the poles are closer to the center of the Earth than people standing at sea level near the Equator. The equatorial bulge affects the ocean, too—sea levels are slightly higher in equatorial regions than near the poles.
Wybrzuszenie równikowe a ruchy powłoki ziemi
Topnienie Arktyki
Zmiany poziomu morza na równiku
W latach 1700-1800 czapa lodu arktycznego narastającego w wyniku ruchu powłoki ziemi na północ wypierała wodę w Arktyce i poziom morza w NW Europie się podnosił. Jednocześnie dawne równikowe obszary zbliżały się do bieguna północnego i zjawisko bulwy równikowej słabło-poziom morza dawnych mórz równikowych obniżał się.
https://eclipse.gsfc.nasa.gov/SEcat5/SE1701-1800.html
Five Millennium Catalog of Solar Eclipses
1701 to 1800 ( 1701 CE to 1800 CE )
can only occur when the Moon is near one of its two orbital nodes [1] during the New Moon phase. It is then possible for the Moon’s penumbral, umbral or antumbral shadows to sweep across Earth’s surface thereby producing an eclipse. There are four types of solar eclipses:
- Partial – Moon’s penumbral shadow traverses Earth (umbral and antumbral shadows completely miss Earth)
- Annular – Moon’s antumbral shadow traverses Earth (Moon is too far from Earth to completely cover the Sun)
- Total – Moon’s umbral shadow traverses Earth (Moon is close enough to Earth to completely cover the Sun)
- Hybrid – Moon’s umbral and antumbral shadows traverse Earth (eclipse appears annular and total along different sections of its path). Hybrid eclipses are also known as annular-total eclipses. [2]
Total eclipses are visible from within the Moon’s umbral shadow while annular eclipses are seen within the antumbral shadow . These eclipses can be classified as central [3] or non-central as:
- Central (two limits) – The central axis of the Moon’s shadow cone traverses Earth thereby producing a central line in the eclipse track. The umbra or antumbra falls entirely upon Earth so the ground track has both a northern and southern limit.
- Central (one limit) – The central axis of the Moon’s shadow cone traverses Earth. However, a portion of the umbra or antumbra misses Earth throughout the eclipse and the resulting ground track has just one limit.
- Non-Central (one limit) – The central axis of the Moon’s shadow cone misses Earth. However, one edge of the umbra or antumbra grazes Earth thereby producing a ground track with one limit and no central line.
The recurrence of solar eclipses is governed by the Saros cycle. For more information, see Periodicity of Solar Eclipses.
[1] The Moon’s orbit is inclined about 5.1° to Earth’s orbit around the Sun. The points where the lunar orbit intersects the plane of Earth’s orbit are known as the nodes. The Moon moves from south to north of Earth’s orbit at the ascending node, and from north to south at the descending node.
Periodicity of Solar Eclipses
Fred Espenak, NASA’s GSFC
https://eclipse.gsfc.nasa.gov/SEsaros/SEperiodicity.html
1.1 Eclipse Seasons
The orbit of the Moon around Earth is inclined about 5.1° to Earth’s orbit around the Sun. As a consequence, the Moon’s orbit crosses the ecliptic at two points or nodes. If New Moon takes place within about 17° of a node[1], then a solar eclipse will be visible from some location on Earth.
The Sun makes one complete circuit of the ecliptic in 365.24 days, so its average angular velocity is 0.99° per day. At this rate, it takes 34.5 days for the Sun to cross the 34° wide eclipse zone centered on each node. Because the Moon’s orbit with respect to the Sun has a mean duration of 29.53 days, there will always be one and possibly two solar eclipses during each 34.5-day interval when the Sun passes through the nodal eclipse zones. These time periods are called eclipse seasons.
The mid-point of each eclipse season is separated by 173.3 days which is the mean time for the Sun to travel from one node to the next. The period is a little less that half a calendar year because the lunar nodes slowly regress westward by 19.3° per year.
[1] The actual value ranges from 15.39° to 18.59° because of the eccentricity of the Moon’s (and Earth’s) orbit.
1.2 Interval Between Two Successive Solar Eclipses
The time interval between any two successive solar eclipses can be either 1, 5, or 6 lunations (synodic months).
Earth will experience 11,898 eclipses of the Sun during the 5000-year period from -1999 to +3000 (2000 BCE to 3000 CE [2]). As published in in both the Five Millennium Canon of Solar Eclipses and Five Millennium Catalog of Solar Eclipses, the distribution of the 11,897 intervals between these eclipses is found in Table 1.
| Table 1 – Interval Between Successive Solar Eclipses | ||
| Number of Lunations | Number of Eclipses | Percent |
| 1 | 1,361 | 11.4% |
| 5 | 2,743 | 23.1% |
| 6 | 7,793 | 65.5% |
[2] The terms BCE and CE are abbreviations for “Before Common Era” and “Common Era,” respectively. They are the secular equivalents to the BC and AD dating conventions. (See: Year Dating Conventions )
I got the news about the number of solar eclipses from the website entitled Five Millennium Catalog of Solar Eclipses-link:
https://eclipse.gsfc.nasa.gov/SEcat5/SE1701-1800.html .
I learned about the causes of changes in the number of eclipses while reading the Periodicity of Solar Eclipses by Fred Espenak, NASA’s GSFC link: https://eclipse.gsfc.nasa.gov/SEsaros/SEperiodicity.html .
The number of solar eclipses depends on the tilt of the Moon’s orbit to the Earth’s orbit around the Sun and the eccentricity of the Moon’s and Earth’s orbits.
I took information about earthquakes from catalogs:
Guidoboni, Emanuela, Comastri, Alberto, Traina, Giusto. 1994. Catalog of ancient earthquakes in the Mediterranean area up to the 10th century. Rome: Instituto Nazionale de Geofisica.
Guterch, Barbara, Lewandowska – Marciniak, Hanna. 2002. “Seismicity and seismic hazard in Poland.” Quaternaria vol.73 foil. Cracow.
The clear correlation shown in the figure above between the number of eclipses and the number of earthquakes is disturbed in the years 700-1500 CE and I cannot explain it. The logical conclusion from the figure is that changes in gravity within the solar system affecting the orbits of its objects determine the number of earthquakes and changes in the climate on Earth. I described these processes in more detail in my open access book in Google Books entitled The new look at the Earth’s climate mechanism and the Cosmo-geophysical system of the Earth, link:
https://play.google.com/store/books/details/ Bogdan_G% C3% B3ralski_The_new_look_at_the_Earth_s_climat? Id = eZu-DwAAQBAJ
Wiadomości o liczbie zaćmień Słońca zaczerpnąłem ze strony internetowej zatytułowanej Five Millennium Catalog of Solar Eclipses-link:
https://eclipse.gsfc.nasa.gov/SEcat5/SE1701-1800.html .
Wiedzę o przyczynach zmian liczby zaćmień zdobyłem podczas lektury podstrony powyższego katalogu zatytułowanej Periodicity of Solar Eclipses by Fred Espenak, NASA’s GSFC link: https://eclipse.gsfc.nasa.gov/SEsaros/SEperiodicity.html.
Liczba zaćmień Słońca zależy od nachylenia orbity Księżyca do orbity Ziemi wokół Słońca and the eccentricity of the Moon’s and Earth’s orbits.
Informacje o trzęsieniach ziemi zaczerpnąłem z katalogów:
Guidoboni, Emanuela, Comastri, Alberto, Traina, Giusto. 1994. Catalogue of ancient earthquakes in the Mediterranean area up to the 10th century. Rome: Instituto Nazionale de Geofisica.
Guterch, Barbara, Lewandowska – Marciniak, Hanna. 2002. “Seismicity and seismic hazard in Poland.” Folia Quaternaria vol.73. Kraków.
Przedstawiona na powyższym rysunku wyraźna korelacja pomiędzy liczbą zaćmień a liczbą trzęsień ziemi jest zaburzona w latach 700-1500 CE i nie potrafię tego wyjaśnić. Logicznym wnioskiem z rysunku jest to, że zmiany sił grawitacji w obrębie Układu Słonecznego wpływające na orbity jego obiektów decydują o liczbie trzęsień ziemi i zmianach klimatu na Ziemi. Procesy te opisałem dokładniej w mojej książce opublikowanej w wolnym dostępie w Google Books zatytułowanej The new look at the Earth’s climate mechanism and the Cosmo-geophysical system of the Earth, link: https://play.google.com/store/books/details/Bogdan_G%C3%B3ralski_The_new_look_at_the_Earth_s_climat?id=eZu-DwAAQBAJ