NAIPburp

Model carbon emissions from the North Atlantic Igneous Province

NAIPburp contains multiple stochastic models for carbon-based greenhouse gas emissions from the North Atlantic Igneous Province (NAIP). These histories were calculated using code in GitHub repositories smj75/sillburp and smj75/LIPburp.

The primary reference is, "Jones, S. M., Hoggett, M., Greene, S. E. & Dunkley Jones, T., Large Igneous Province thermogenic greenhouse gas flux could have initiated Paleocene-Eocene Thermal Maximum climate change, Nature Communications, in press Sept 2019," referred to below as Jea19.

There are 3 types of data here.

1. DATASETS of NAIP sill province dimensions used to generate the results

Measurements of sill surface area, A in km2

Used in Jea19, Fig. 4a.
sill_areas_3D_naip_over10km2.x (this distribution used for stochastic modelling).
sill_areas_2D_naip_corr_over10km2
Judd.txt
FSB.txt
More.txt
IrishRockall.txt
Rockall2D.txt
SlyneErris.txt.

Measurements of sill emplacement depth, Z in km.

emplacement_depth.gmt contains the data, the approximation used in stochastic modelling and the plotting script for Jea19, Fig. 4b.

Measurements of maximum thickness, S in m, as a function of measured maximum sill radius, R in km

thickness_diameter.gmt contains the data, the approximation used in stochastic modelling and the plotting script for Jea19, Fig. 4c.

Measurements of sill thickness, s in m, as a function of distance from sill centre, r in km

thickness_profile.gmt contains the data, the approximations used in stochastic modelling and the plotting script for Jea19, Fig. 4d.

Host rock TOC measurements, w_CH4, in %

host_toc.gmt contains the data, the approximation used in stochastic modelling and the plotting script for Jea19, Fig. 4e.

Parameterisation of (M_therm, tau_decay, p) as functions of (s, Z) used to simulate emissions from individual sills

aureole_parameterisation.txt records the parameterisation in the format needed by smj75/LIPburp/dim2mpt.awk. See smj75/sillburp* for calculation method.

Area function, Gamma

dadr_ellipse_deepchain_max_72.awk is the function used for all calculations in Jea19 in the format needed by smj75/LIPburp/LIP_emission_model.awk.

2. RESULTS of greenhouse gas emissions modelling using the NAIP sill measurements and constant values of tau_repeat, the time between intrusion of successive sills

These results were used in Fig. 5 of Jea19.

Files are named const_trec_[A]yr_emissions_model_[B]yr.[N], where [A] is the constant value of tau_repeat, [B] is the time period over which the measurements are averaged, and [N] is the stochastic run number.

The columns in each emissions_model file are as below.

3. RESULTS of greenhouse gas emissions modelling using the NAIP sill measurements and time-dependent tau_repeat, specified by a mantle convection model

These results were used in Fig. 8 of Jea19.

Files are named emissions_model_[B]yr_q[Q].[N] and sills_model_[B]yr_q[Q].[N], where [B]is the time period over which the measurements are averaged, [Q] is the mantle plume area flux, and [N] is the stochastic run number.

The columns in each emissions_model file are:

1. Time relative to first sill (yr)
2. Total carbon flux at this time step (PgC/yr)
3. Carbon flux from thermogenic methane at this time step (PgC/yr)
4. Carbon flux from CO2 degassed from sill magma at this time step (PgC/yr)
5. Carbon flux from CO2 degassed from lavas at this time step (PgC/yr)
6. Fraction of total carbon supplied as thermogenic methane at this time step
7. Total cumulative carbon mass up to this time (PgC)
8. Carbon mass from thermogenic methane up to this time (PgC)
9. Carbon mass from CO2 degassed from sill magma up to this time (PgC)
10. Carbon mass from CO2 degassed from lavas up to this time (PgC)
11. Cumulative Carbon isotope composition of all carbon emitted from province (per mil)
12. Carbon isotope composition of thermogenic+mantle emissions at this time step (per mil)
13. Sill recurrence time (yr)
14. Absolute age (yr)
15. Long radius of mantle thermal anomaly marker (km)
16. Time step number (= sill number)
17. Mean carbon flux from thermogenic methane at this time step (PgC/yr)

The columns in each sills_model file are:

1. Intrusion time (yr)
2. Total mass of thermogenic methane-derived carbon per unit surface area (PgC/km2)
3. Total mass of carbon degassed from magma (PgC/km2)
4. Maturation decay time (yr)
5. Time to establishment of vent (yr)
6. Time to solidification of magma (yr)
7. Time after pulse left plume centre (yr)
8. Sill recurrence time (yr)
9. Maximum pulse radius (km)
10. Sill location radius (km)
11. Sill location azimuth (azimuth)
12. Number of overlapping sills
13. Overlapped percentage of aureole footprint, this sill
14. Overlapped percentage of aureole volume, this sill
15. Overlapped percentage of aureole footprint, whole province
16. overlapped percentage of aureole volume, whole province