4 ms·

I was quite curious about this project a while back. But I later talked to an academic, a friend who happens to be an expert in the kinds of reaction kinetics t

I was quite curious about this project a while back. But I later talked to an academic, a friend who happens to be an expert in the kinds of reaction kinetics the project relies on. His view was that they are not using the correct reaction rates in their calculations. He said they were linearly extrapolating existing data, when in reality it is a non-linear relationship. So my understanding is that their reaction rates still need to be empirically validated. Disappointingly, my friend had no faith that this would ever work - although academics have of course been wrong before. Regardless, I'm very interested to see how this project plays out.

ProjectVesta 7y ago
Hi Funklute, most of the models out there for dissolution kinetics and weathering rates are a type called "shrinking core models" such as those used in analysis by Hangx and Spiers (2009). Those models definitely do not take into account the effect of grain-on-grain collisions, surface abrasion, the constant refreshing of warm, acidic water, and/or fauna such as lugworms[1]. For example, the constant collisions chip off fine fractions of olivine that themselves weather rapidly. And the constant grinding removes a silica coating that dramatically slows the weathering rate of stationary olivine. Lugworm digestion can speed up the weathering rate by 100x-1000x, etc. Ask your friend if he knows of any models that take even some of these considerations into account, as all of them will be present in the coastal environment and contribute to our accelerated weathering rates. Also, please show him these simple desktop shaker experiments here [2] and here [3], that show the rates are much higher than the core shrinking models calculate when the olivine is in motion (and these experiments are in fairly cold water compared to the tropics). This is the type of research that we base our calculations on. That said, we are in agreement that we need the rates to be empirically validated. So, first we are going to deploy a Phase Ia Safety Pilot Study, and once that is on the beach we will begin work on our Phase Ib Speed Pilot Study to demonstrate the accelerated rates. Thank you for your optimism for the project, we welcome feedback and hope to help spread the understanding of the underlying processes that make the project viable :) [1] https://projectvesta.org/science/#dflip-df_88/1/ https://projectvesta.org/science/#dflip-df_88/1/ [2] https://projectvesta.org/science/#dflip-df_67/4/ https://projectvesta.org/science/#dflip-df_67/4/ [3] https://projectvesta.org/science/#dflip-df_90/9/ https://projectvesta.org/science/#dflip-df_90/9/

ProjectVesta 7y ago

Hi Funklute, most of the models out there for dissolution kinetics and weathering rates are a type called "shrinking core models" such as those used in analysis by Hangx and Spiers (2009). Those models definitely do not take into account the effect of grain-on-grain collisions, surface abrasion, the constant refreshing of warm, acidic water, and/or fauna such as lugworms[1]. For example, the constant collisions chip off fine fractions of olivine that themselves weather rapidly. And the constant grinding removes a silica coating that dramatically slows the weathering rate of stationary olivine. Lugworm digestion can speed up the weathering rate by 100x-1000x, etc. Ask your friend if he knows of any models that take even some of these considerations into account, as all of them will be present in the coastal environment and contribute to our accelerated weathering rates. Also, please show him these simple desktop shaker experiments here [2] and here [3], that show the rates are much higher than the core shrinking models calculate when the olivine is in motion (and these experiments are in fairly cold water compared to the tropics). This is the type of research that we base our calculations on. That said, we are in agreement that we need the rates to be empirically validated. So, first we are going to deploy a Phase Ia Safety Pilot Study, and once that is on the beach we will begin work on our Phase Ib Speed Pilot Study to demonstrate the accelerated rates. Thank you for your optimism for the project, we welcome feedback and hope to help spread the understanding of the underlying processes that make the project viable :) [1] https://projectvesta.org/science/#dflip-df_88/1/ https://projectvesta.org/science/#dflip-df_88/1/ [2] https://projectvesta.org/science/#dflip-df_67/4/ https://projectvesta.org/science/#dflip-df_67/4/ [3] https://projectvesta.org/science/#dflip-df_90/9/ https://projectvesta.org/science/#dflip-df_90/9/