Earth Science

Hi everyone, SO im new to this but im desperate for a little help understanding something... Seismometers. the time that elapses between an earthquake and it being recorded by the seismometer depends on what factors? Is it the different type of waves? ANY help would be incredibly appreciated! Thanks in advance!

Hello to all, this is my first post Yesterday (3/20/10) was the solstice, which gives us equal parts light and dark, thus marking the beginning of spring in the northern hemisphere. When however I went to view an annual chart for my location (Portland, Oregon), the sunrise was listed at 7:14AM and sunset at 7:23PM. This chart lists march 17th as having a sunrise and sunset at 7:19 AM and PM... So why the discrepancy? Also, While looking for an answer to the question above, I found many references to the earth having a tilted axis. And while there is an abundance of information about the effects of this tilt on our environment, there is no information about…

I realized that although certain ecological niches were dominated by Dinosaurs on the continents, the numerous small islands, no doubt many due to the increase volcanism, could open up those ecological niches to mammals. It could have been possible that for the 175MY reign of the Dinosaurs could have hosted many large mammals such as those of the Pleistocene after they went extinct.

I have this geode that my cousin gave to me a few years ago. I was wondering how much it's worth. A geography teacher told me that it's exceptionally rare, but I'd love to know more about it. These pictures should be enough of a description. So, it's about 9cm long, 6.5cm wide, and 3.5 deep in a rough dome shape. How much could it be worth? Thanks. EDIT: I also have a higher res overview: IMG_6887.JPG

I have new theory regarding birth of earth. Pls see below point wise. 1. Earth has biological growth like a tree and meteoroids are seeds of planets. 2. only some meteoroids can germinate in asteroids and some asteroids can convert in big planets only 3. Earth has bark like a tree and this bark is separated from each other. Continents is a bark of earth. 4. Earth is a result of one meteor only. It is germinated from single meteor. 5. Earth has all minerals same required by living thing. 6. Different different pockets of minerals shows that it has biological thing only. No other theory applicable of earth formation if it has different different pockets of miner…

http://www.csmonitor.com/Science/Discoveries/2010/0303/Chile-earthquake-shortened-Earth-s-day-NASA-thinks-so The Chilean earthquake displaced enough of the Earth's mass to affect its axis and shortened the length of the day by approximately one microsecond. I heard a great NPR interview with a NASA geophysicist about this. Apparently they managed to perform this calculation using seismic data alone.