Soliciting Ideas for "Research Proposals" GeoPhysics

[RJLiberator]

Hello Physics Forums,

For my Geophysics course we are going to be outlining and presenting a 'proposed study' for a geophysical research assignment. We will not be going through with the study, but rather outline it, propose it, and show our expected results.

I wanted to try to farm some ideas from the great minds here. If you were posed with this scenario, what would you like to explore?

In our class we have used magnetic anomalies of the seafloor, GPS data, analyzing heat flow within the earth, seismic studies, plate boundary studies, using seismometers to analyze different phenomena.

Is there any ideas of study that you have?

 

[Geofleur]

How about computational modeling of the recurring slope lineae on Mars? It's a different planet, but many of the same principles apply.

 

[RJLiberator]

That's actually a really great idea -- looking at the geophysical processes of another planet, namely Mars.

I'm not entirely sure with what you mean by slope lineae, but you've granted me some creative thoughts!

 

[Geofleur]

This might help: https://en.wikipedia.org/wiki/Seasonal_flows_on_warm_Martian_slopes

 

[Jimbo4606]

Hi - I'll offer up an idea I posted on the Earth Science Stack Exchange a few days ago (what follows is pretty much a cut-and-paste job, slightly edited):

Are there any examples of now completely landlocked former river mouths or estuaries that became so after continental collision? As an example, consider the closure of the ocean between India and the Eurasian Plate – is there any evidence today, e.g. up in the Himalayas, of ancient river mouths or estuaries that are now stranded on the convergent boundary of the two continents? As a corollary are there any rivers today which contain evidence of an opposite flow direction in the past, as a consequence of continental collision? Such cases, if they exist, would be interesting mirrors to the idea of continental rifting's contribution to river flow reversal (I'm thinking of the extraordinary discovery of the River Amazon's former east-to-west flow before South America rifted away from Africa).

The guy who replied to my questions (a professional geologist/hydrologist) said that there would be no evidence left of river mouths or estuaries due to erosion, etc., in the Himalayas region. (But maybe there's some evidence if one knew what to look for? I don't know, speaking as a physicist!) However, there can indeed be evidence of river flow reversal in the past, e.g. the Amazon's reversal was discovered by accident when researchers found sediment deposits somewhere along its path that could only have come from a location further downstream - hope this is of some interest to you :)

References:
http://www.livescience.com/4253-amazon-river-flowed-ancient-times.html
http://Earth'science.stackexchange....ft-of-river-mouths-and-estuaries-along-the-bo

 

[RJLiberator]

Hey guys, just wanted to bump this post one time to see if there are any interesting ideas out there that involve the topics covered in this thread.

Simple ideas?

 

[Jimbo4606]

Ok, some simple (sort of!) ideas off the top of my head: 1) Compare the magnetism of rock within asteroidal/large meteorite impact craters vs. the magnetism of the (same) surrounding rock – any difference in magnetism between the two, e.g. due rock melting at the time of impact? 2) Look at the magnetism of volcanic islands or the solidified lava in seamounts (undersea volcanoes) compared to the surrounding oceanic crust – if an island or seamount formed (much) later than the surrounding crust, e.g. during a time when the Earth's magnetic field had reversed compared to the area of oceanic crust it stands on, is there evidence of this with a comparison of the rocks' magnetic properties? 3) At an active plate boundary, obtain distances between locations on each side of the boundary using GPS, and also take local seismic readings – any correlation observed between seismic activity and associated relative movements of those neighbouring plates, e.g. how about the San Andreas fault as an interesting location?

 

[RJLiberator]

Jimbo, thanks for the ideas.

1. Comparing magnetism of rocks within asteroidal impact craters vs. magnetism of the surrounding rock.
Cool idea, this might be an awesome hypothetical project to talk about. I'm not sure how I'd collect this data, but we did talk a lot about magnetism in rocks.

2) Volcanic island magnetism
Excellent idea for my class, spot on. I will talk about this one with the group.

3) We have already discussed the San Andreas fault and this technique in our class quite a lot. :).

Thank you kindly for the suggestive ideas.

 

[Jimbo4606]

Glad to be of help, RJLiberator :) And yeah, you're right about the San Andreas Fault - it's probably been done to death as a classic example of a continental transform fault. Here are some final ideas that have since come to mind – look at the paleomagnetism of (volcanic) sites vs. their historic latitudes. As an extreme case, have a look at places that may once have been located near one of the Poles, e.g. I think Africa was once located over or near the South Pole once; any evidence of this in the magnetic field direction recorded by molten rock that solidified at the time (and therefore more evidence for continental drift)? Also, how about some laboratory-based work? For example, melt different volcanic rock types (having measured their magnetism beforehand) and let the stuff cool down in applied magnetic fields, e.g. simulating the Earth's current field strength, historic field strengths, etc. Then measure the magnetism of the solidified rock; compare the magnetism of different re-solidified samples for the same applied field, compare their resultant magnetic fields to the known applied fields, dependency on the starting quantity of melt, the rate of cooling (assuming the cooling rate can be measured/controlled), etc. - you'd have to check how the re-solidified rock's crystalline structure compared with the original (this might be a source of difference or not but, as a good scientist, you'd make a note of it in case it's important). All the best for your class project, J :)

 

[Geology Erwin]

You could use electric properties of groundwater solutions tot model different types of groundwater in an aquifer.

• You could try to map the boundary zone between salt water and fresh water in a coastal dune system and see how it responds to climate and/or fresh water extraction.
  This would have practical applications. How much development of a coastal zone can sustainably be provided with local fresh water. What do you expect to happen in case of an el nino event ?
  
  You could also do this for an aquifer in a limestone region such as the Yucatan Peninsula and Florida.
• Something similar could be done with respect to polluted groundwater or even non aquaeous liquids penetrating a groundwater body.
• You could the same electric properties or sound properties to determine which concrete slabs along a river are being undercut by the waterflow.