# New on StackExchange: Temporal Resolution of Seismic data

Radius of the Fresnel zone is given by $Rf=(v/2)(t_0/f_\mathrm{dom})^{1/2}$ where v: velocity of layer $t_0$: two way travel time $f_\mathrm{dom}$ :dominant frequency in the spectrum This shows that high frequencies give better resolution than lower frequencies and resolution deteriorates with depth and increasing velocities. However I found some text in “Seismic Data Analysis- Yilmaz” which […]

# To what accuracy and precision do we know the volume of the Earth?

Satellites such as GOCE and GRACE measure the geoid with unprecedented accuracy. Altimeters can determine local surface elevation with millimetre-precision. This makes me wonder: to what precision and accuracy can we measure (or calculate) the volume of the Earth? I’m a lay when it comes to solid Earth, and I find it surprisingly hard to […]

# Dante’s Peak investigated

Dante’s Peak, one of those disaster movies that you either love or hate. Pierce Brosnan saves a dog from Old Smokey tantrum. In the role of a volcanologist we get quite a bit of action such as this scene: Now Rebecca Williams from the University of Hull has taken a closer look at the movie. […]

# Shock Waves on Tavurvur – Volcano Monday

The shock wave on the Tavurvur volcano in Papua New Guinea is really quite impressive!

# A geologic mystery solved! – The sailing stones

When you write about geology you inevitably come across a couple mysteries that are just unsolved. In the Racetrack Playa in Death Valley they have many names for this phenomenon. Racing Rocks Sailing Stones Wandering Stone Moving Stones In the end they were just as puzzling. These rocks were moving without any apparent force moving […]

# The Showroom – Data for my thesis

I’m working on a field data set from the Mediterranean Sea. There are many intellectual reasons for working this data set. However, there are some motivate my inner child as well, let me explain. The Specs The data set was recorded by TGS and is of brilliant quality. Almost 8km (5mi) in offset over the […]

# The end is near! – My Master Thesis

I just started the end of my journey in university. I registered my Master’s thesis. This feels like quite the step and I’m very proud I’ve come so far. Today I start the last chapter of my studies. In half a year's time I'll finish my Master's. Exciting times lie ahead. — Jesper Dramsch (@JesperDramsch) […]

# Quadcopters and Volcanoes = awesome!

Today’s volcano is featured by a quadcopter. Be sure to check out this amazing footage! from Tumblr

# Do you know your seismic velocity?

In seismic data analysis a lot of work goes towards getting a good velocity model of the subsurface. We talk about the seismic velocity. However, this may lead to some serious misconceptions. One step in seismic processing is velocity analysis. We pick the velocity that adjusts our data for the best value. Usually this is […]