NASA Missions to Enable Critical Solid Earth Science Observations

+---------------+---------------+-------------------+-----------------+
| Science       | Information   | Observation Needs | NASA            |
| Questions     | Needs         |                   | Observations    |
+---------------+---------------+-------------------+-----------------+
| What is the   | Earth surface | mm/yr-level 3D    | Repeat-pass     |
| nature of     | motion        | surface           | InSAR           |
| deformation   | throughout    | deformation       |                 |
| at plate      | seismic cycle |                   |                 |
| boundaries?   |               |                   |                 |
+---------------+---------------+-------------------+-----------------+
|               | Subsurface    | -   Subsurface    | Low-frequency   |
|               | ch            |     layer         | EM sounding     |
|               | aracteristics |     location and  |                 |
|               |               |     geometry to   |                 |
|               |               |     150 Km depth  |                 |
|               |               |                   |                 |
|               |               | -   Mechanical    |                 |
|               |               |     properties of |                 |
|               |               |     the           |                 |
|               |               |     subsurface    |                 |
|               |               |     layers        |                 |
+---------------+---------------+-------------------+-----------------+
|               | Sea floor     | mm/yr-level 3D    | Repeat-pass     |
|               | geodesy       | surface           | InSAR           |
|               |               | deformation       |                 |
+---------------+---------------+-------------------+-----------------+
|               | Gravity       | High-accuracy,    | Post-GRACE      |
|               | Anomalies     | sub-Km-scale      | Gravity         |
|               |               | resolution vector | Missions        |
|               |               | gravity signal    |                 |
+---------------+---------------+-------------------+-----------------+
| How do        | Topography    | 3D surface        | Topographic     |
| tectonic,     |               | topography at     | InSAR           |
| geomorphic,   |               | various           |                 |
| climatic, and |               | resolution scales | Laser altimetry |
| biologic      |               |                   |                 |
| processes     |               |                   |                 |
| interact to   |               |                   |                 |
| shape the     |               |                   |                 |
| landscape and |               |                   |                 |
| create        |               |                   |                 |
| Natural       |               |                   |                 |
| hazards?      |               |                   |                 |
+---------------+---------------+-------------------+-----------------+
|               | Topographic   | Mm/yr level 3D    | Repeat-pass     |
|               | change        | surface           | InSAR           |
|               |               | deformation       |                 |
+---------------+---------------+-------------------+-----------------+
|               | Subsurface    | -   Subsurface    | Low-frequency   |
|               | ch            |     layer         | EM Sounding     |
|               | aracteristics |     location and  |                 |
|               |               |     geometry to   |                 |
|               |               |     150 Km depth  |                 |
|               |               |                   |                 |
|               |               | -   Mechanical    |                 |
|               |               |     properties of |                 |
|               |               |     the           |                 |
|               |               |     subsurface    |                 |
|               |               |     layers        |                 |
+---------------+---------------+-------------------+-----------------+
|               | Surface       | Geometric,        | Hyperspectral   |
|               | materials     | electrical,       | TIR             |
|               |               | thermal           |                 |
|               |               | properties        | Multiparameter  |
|               |               |                   | SAR             |
+---------------+---------------+-------------------+-----------------+
|               | Weather and   | -   Rainfall      | Rain Radar      |
|               | climate       |     amount and    |                 |
|               |               |     rate          | Multiparameter  |
|               |               |                   | SAR             |
|               |               | -   Soil moisture |                 |
+---------------+---------------+-------------------+-----------------+
|               | Vegetation    | -   Vegetation    | Mult            |
|               | properties    |     classes       | i/hyperspectral |
|               |               |                   | IR/VNIR/TIR     |
|               |               | -   Vegetation    |                 |
|               |               |     biomass       | Multiparameter  |
|               |               |     change        | SAR             |
+---------------+---------------+-------------------+-----------------+
|               | Surface ages  | -   Rate of       | None.           |
|               |               |     deposition    |                 |
|               |               |                   |                 |
|               |               | -   Rate of       |                 |
|               |               |     exhumation    |                 |
+---------------+---------------+-------------------+-----------------+
| What are the  | Ice surface   | Sub-meter 3D      | Laser altimetry |
| interactions  | topography    | surface           |                 |
| among ice     |               | topography        | Topographic     |
| masses,       |               |                   | InSAR           |
| oceans, and   |               |                   |                 |
| the solid     |               |                   |                 |
| Earth and     |               |                   |                 |
| their         |               |                   |                 |
| implications  |               |                   |                 |
| for sea level |               |                   |                 |
| rise?         |               |                   |                 |
+---------------+---------------+-------------------+-----------------+
|               | Ice flow      | m/yr vector ice   | Repeat-pass     |
|               | velocity      | velocity          | InSAR           |
+---------------+---------------+-------------------+-----------------+
|               | Ice volume,   | 10-m accuracy ice | Low-frequency   |
|               | bed           | thickness         | EM sounding     |
|               | conditions    |                   |                 |
+---------------+---------------+-------------------+-----------------+
|               | Ice mass flux | -   Above three   | Post-GRACE      |
|               |               |     observations  | gravity         |
|               |               |                   | missions        |
|               |               | -   Time-varying  |                 |
|               |               |     gravity to    |                 |
|               |               |     500-Km        |                 |
+---------------+---------------+-------------------+-----------------+
|               | Snow/ice      | -   Sub-Km snow   | -               |
|               | albedo        |     location and  |  Multiparameter |
|               |               |     extent        |     SAR         |
|               |               |                   |                 |
|               |               | -   Surface       | -   Mult        |
|               |               |     optical       | i/hyperspectral |
|               |               |     reflectivity  |     IR/VNIR/TIR |
|               |               |                   |                 |
|               |               | -   Surface       | -   Microwave   |
|               |               |     microwave     |     radiometer  |
|               |               |     emissivity    |                 |
+---------------+---------------+-------------------+-----------------+
|               | Ocean         | Surface microwave | Microwave       |
|               | salinity      | emissivity        | radiometer      |
+---------------+---------------+-------------------+-----------------+
|               | Sea ice cover | \<50m ice         | Multiparameter  |
|               |               | location and      | SAR             |
|               |               | extent            |                 |
+---------------+---------------+-------------------+-----------------+
|               | Coastal       | \<10m resolution  | -               |
|               | boundary      | coastline         |  Multiparameter |
|               | changes       | location and      |     SAR         |
|               |               | properties        |                 |
|               |               |                   | ```{=html}      |
|               |               |                   | <!-- -->        |
|               |               |                   | ```             |
|               |               |                   | -   Mult        |
|               |               |                   | i/hyperspectral |
|               |               |                   |     IR/VNIR/TIR |
+---------------+---------------+-------------------+-----------------+

+----------------+----------------+--------------------+---------------+
| Science        | Information    | Observation Needs  | NASA          |
| Questions      | Needs          |                    | Observations  |
+----------------+----------------+--------------------+---------------+
| How do         | Surface motion | mm/yr-level 3D     | Repeat-pass   |
| magmatic       | of volcanoes   | surface            | InSAR         |
| system evolve, |                | deformation        |               |
| and under what |                |                    |               |
| conditions do  |                |                    |               |
| they erupt?    |                |                    |               |
+----------------+----------------+--------------------+---------------+
|                | Subsurface     | -   Subsurface     | Low-frequency |
|                | c              |     layer location | EM sounding   |
|                | haracteristics |     and geometry   |               |
|                |                |     to 150 Km      |               |
|                |                |     depth          |               |
|                |                |                    |               |
|                |                | -   Mechanical     |               |
|                |                |     properties of  |               |
|                |                |     the subsurface |               |
|                |                |     layers         |               |
+----------------+----------------+--------------------+---------------+
|                | seismicity     | 0-15 Km subsurface | Repeat-pass   |
|                |                | layer location     | InSAR         |
+----------------+----------------+--------------------+---------------+
|                | Silica content | Silica content of  |               |
|                | of Magma       | crystaline rocks   |               |
+----------------+----------------+--------------------+---------------+
|                | Gas emission   | Thermal changes to | Hyperspectral |
|                | rate           | 0.5K               | TIR           |
+----------------+----------------+--------------------+---------------+
|                | Time-series    | -   Thermal        | Hyperspectral |
|                | thermal        |     changes to 0.5 | TIR           |
|                | changes        |     K              |               |
|                |                |                    |               |
|                |                | -   Temperature to |               |
|                |                |     0.5K           |               |
+----------------+----------------+--------------------+---------------+
|                | Ionospheric    | Changes in         |               |
|                | changes        | electric field     |               |
+----------------+----------------+--------------------+---------------+
|                | Gravity        | High-accuracy,     | Post-GRACE    |
|                | Anomalies      | sub-Km-scale       | Gravity       |
|                |                | resolution vector  | Missions      |
|                |                | gravity signal     |               |
+----------------+----------------+--------------------+---------------+
|                | Plume/ash      | -   Distinguish    | Multi/        |
|                | properties     |     ash and met    | Hyperspectral |
|                |                |     cloud          | TIR/IR/VNIR   |
|                |                |                    |               |
|                |                | -   Thermal        |               |
|                |                |     changes to     |               |
|                |                |     0.3K           |               |
|                |                |                    |               |
|                |                | -   Co2 Column     |               |
|                |                |     abundance to   |               |
|                |                |     0.5g/m2        |               |
+----------------+----------------+--------------------+---------------+
|                | topography     | -   10-cm level    | Topogaphric   |
|                |                |     topography     | InSAR         |
+----------------+----------------+--------------------+---------------+
|                | Surface        | -   m/s level flow | -             |
|                | charateristics |     velocity       |   Repeat-pass |
|                |                |                    |     InSAR     |
|                |                | -   1K level flow  |               |
|                |                |     temperature    | -             |
|                |                |                    | Hyperspectral |
|                |                | -   roughness and  |     TIR       |
|                |                |     topography     |               |
+----------------+----------------+--------------------+---------------+
|                | Post-eruption  | -   m/s level flow | -             |
|                | flow type      |     velocity       |   Repeat-pass |
|                |                |                    |     InSAR     |
|                |                | -   1K level flow  |               |
|                |                |     temperature    | ```{=html}    |
|                |                |                    | <!-- -->      |
|                |                | -   roughness and  | ```           |
|                |                |     topography     | -             |
|                |                |                    | Hyperspectral |
|                |                |                    |     TIR       |
+----------------+----------------+--------------------+---------------+
| What are the   | Post-glacial   | -   mm/yr 3D       | -             |
| dynamics of    | relaxation     |     surface        |   Repeat-pass |
| the mantle and |                |     deformation    |     InSAR     |
| crust, and how |                |                    |               |
| does the       |                | -   Secular        | -             |
| Earth's        |                |     ime-varying    |    Post-GRACE |
| surface        |                |     gravity        |     gravity   |
| respond?       |                |                    |     missions  |
|                |                | -   High-accuracy  |               |
|                |                |     few-km vector  |               |
|                |                |     gravity        |               |
+----------------+----------------+--------------------+---------------+
|                | Post-seismic   | -   mm/yr 3D       | -             |
|                | relaxation     |     surface        |   Repeat-pass |
|                |                |     deformation    |     InSAR     |
|                |                |                    |               |
|                |                | -   paleofeature   | -             |
|                |                |     location to mm | Low-frequency |
|                |                |     accuracy       |     EM        |
|                |                |                    |     sounder   |
|                |                | -   Mechanical     |               |
|                |                |     properties of  | -             |
|                |                |     the subsurface |    Post-GRACE |
|                |                |     layers         |     gravity   |
|                |                |                    |     missions  |
+----------------+----------------+--------------------+---------------+
|                | Crustal loads  | -   mm/yr 3D       | -             |
|                |                |     surface        |   Repeat-pass |
|                |                |     deformation    |     InSAR     |
|                |                |                    |               |
|                |                | ```{=html}         | -             |
|                |                | <!-- -->           |    Post-GRACE |
|                |                | ```                |     gravity   |
|                |                | -   High-accuracy  |     missions  |
|                |                |     few-km vector  |               |
|                |                |     gravity        |               |
+----------------+----------------+--------------------+---------------+
|                | Surface        | -   mm/yr 3D       | -             |
|                | displacements  |     surface        |   Repeat-pass |
|                |                |     deformation    |     InSAR     |
|                |                |                    |               |
|                |                | -   Secular        | -             |
|                |                |     ime-varying    |    Post-GRACE |
|                |                |     gravity        |     gravity   |
|                |                |                    |     missions  |
+----------------+----------------+--------------------+---------------+
|                | Changes in     | -   Secular        | Post-GRACE    |
|                | gravity        |     ime-varying    | gravity       |
|                |                |     gravity        | missions      |
|                |                |                    |               |
|                |                | ```{=html}         |               |
|                |                | <!-- -->           |               |
|                |                | ```                |               |
|                |                | -   High-accuracy  |               |
|                |                |     few-km vector  |               |
|                |                |     gravity        |               |
+----------------+----------------+--------------------+---------------+
|                | Length of day  | Earth rotation to  | Post-GRACE    |
|                |                | \<marcsec          | gravity       |
|                |                |                    | missions      |
+----------------+----------------+--------------------+---------------+
|                | Solid Earth    | -   High-accuracy  | Post-GRACE    |
|                | tides          |     few-km vector  | gravity       |
|                |                |     gravity        | missions      |
|                |                |                    |               |
|                |                | ```{=html}         |               |
|                |                | <!-- -->           |               |
|                |                | ```                |               |
|                |                | -   Earth rotation |               |
|                |                |     to \<marcsec   |               |
|                |                |                    |               |
|                |                | -   Earth          |               |
|                |                |     orientation to |               |
|                |                |     \<marcsec      |               |
+----------------+----------------+--------------------+---------------+
| What are the   | Crustal &      | -   Vector mag     | -   Magnetic  |
| dynamics of    | lithospheric   |     field          |               |
| the Earth's    | field          |                    | constellation |
| maagnetic      | measurements   | -                  |               |
| field and its  |                |   Short-wavelength | -   Magnetic  |
| interaction    |                |     mag gradient   |               |
| with the Earth |                |                    |   gradiometer |
| system?        |                | -   Few-Km         |               |
|                |                |     resolution     | -             |
|                |                |     Electron       |   Space-based |
|                |                |     density        |     E-field   |
|                |                |     profiles       |               |
|                |                |                    |  measurements |
|                |                | -   High-res       |               |
|                |                |     electric field |               |
+----------------+----------------+--------------------+---------------+
|                | Core field     | -   Vector mag     | -   Magnetic  |
|                | strength and   |     field          |               |
|                | secular        |                    | constellation |
|                | changes        | -   Few-nT level   |               |
|                |                |     external field | -   Magnetic  |
|                |                |                    |               |
|                |                |                    |   gradiometer |
|                |                |                    |               |
|                |                |                    | -             |
|                |                |                    |   Space-based |
|                |                |                    |     E-field   |
|                |                |                    |               |
|                |                |                    |  measurements |
|                |                |                    |               |
|                |                |                    | -   GPS       |
|                |                |                    |               |
|                |                |                    |   occultation |
+----------------+----------------+--------------------+---------------+
|                | Electrical     | -   Vector mag     | -   Magnetic  |
|                | conductivity   |     field          |               |
|                |                |                    | constellation |
|                |                | -   Few-nT level   |               |
|                |                |     external field | -   Magnetic  |
|                |                |                    |               |
|                |                | -   Few-Km         |   gradiometer |
|                |                |     resolution     |               |
|                |                |     Electron       | -             |
|                |                |     density        |   Space-based |
|                |                |     profiles       |     E-field   |
|                |                |                    |               |
|                |                | -   High-res       |  measurements |
|                |                |     electric field |               |
|                |                |                    | -   GPS       |
|                |                |                    |               |
|                |                |                    |   occultation |
+----------------+----------------+--------------------+---------------+
|                | Length of day  | Earth rotation to  |               |
|                |                | 1ms                |               |
+----------------+----------------+--------------------+---------------+