Convert Megayears to Tropical Years
Convert Megayears (Ma) to Tropical Years (a_trop) instantly and accurately.
Conversion Formula
a_trop = Ma × 1000000.849
About Megayears
A megayear (1 Ma) = 10⁶ yr ≈ 3.156 × 10¹³ s - the timescale of geology and tectonic evolution. The K-Pg mass extinction at 66.0 Ma; Cambrian explosion ~538.8 Ma; Great Oxygenation Event ~2,400 Ma. Plate motion at 2-10 cm/yr = 200-1,000 km per Ma (Atlantic ~3,000 km wider since Pangaea rifting ~200 Ma ago). Background extinction rate measured in extinctions per million species-years. 1 Ma = 10⁶ yr.
About Tropical Years
The tropical year = time from March equinox to the next = 365.24219 days = 31,556,925.2 s - the year that governs the seasons. The Gregorian 97/400 leap rule approximates it as 365.2425 days, leaving a residual drift of only ~26.8 s/year. The tropical year shortens ~0.53 s per century due to tidal deceleration. Persian Solar Hijri and Mayan Haab' calendars also approximate it. 1 a_trop ≈ 365.24219 d.
Quick Reference Table
| Megayears (Ma) | Tropical Years (a_trop) |
|---|---|
| 1 Ma | 1000000 a_trop |
| 2 Ma | 2000000 a_trop |
| 5 Ma | 5000000 a_trop |
| 10 Ma | 10000000 a_trop |
| 25 Ma | 25000000 a_trop |
| 50 Ma | 50000000 a_trop |
| 100 Ma | 100000000 a_trop |