Earth-Tide Corrections

We finally felt our first Costa Rican earthquake! The coolest part was that we were in the center for earthquake research (RSN).

Param and I also went to help a student from Switzerland retrieve seismic data. Unfortunately, someone stole the solar panel. So, we had to take apart the station. The car that we drove in hardly fit us. And then we had to have the equipment.

Getting to the point of the station was also interesting. After a 1.5 hour car ride, we had to take a 5km hike up a volcano. The views were very beautiful. But then, we had to hike the 5km again. This time with equipment.

The project that Param and I are working on is very cool. We are trying to find better model for gravity corrections. One of the models that we are looking at is Earth-Tide corrections. On Monday, July 30, 2018, we set up a gravimeter to measure continuously for about 24 hours. This showed a sinusoidal curve in the gravity measurements which is exactly what you would expect from the tide. There are a few models to use to correct for the tides. However, after applying them, there is still a sinusoidal curve in the data.

Right now, it is very frustrating because non of the models are working. The tide correction curve and the gravity reading curve have a phase shift of about π/2. If the two curves had a phase shift of π , then the correction would be perfect; the gravity reading would be a horizontal line (after correcting for drift). Our job right now is to try to make a correction such that this is the case.