=====================
Ground-Motion Records
=====================

Introduction
------------

The dynamic analyses in this framework employ a comprehensive set of **700 ground-motion records** 
selected from multiple international strong-motion databases. These records span a wide range of 
seismological characteristics to ensure robust representation of ground shaking variability 
across different tectonic environments.


Database Sources
----------------

Records were compiled from five major strong-motion databases:

.. list-table:: Ground-Motion Database Sources
   :header-rows: 1
   :widths: 30 70

   * - Database
     - Description
   * - NGA-West2
     - PEER Next Generation Attenuation database for active shallow crustal regions
   * - NGA-East
     - PEER database for stable continental regions (Eastern North America)
   * - NGA-Sub
     - PEER database for subduction zone earthquakes
   * - KiK-Net
     - Japanese strong-motion network (K-NET and KiK-net)
   * - ESM
     - Engineering Strong-Motion database (European/Mediterranean)


Tectonic Environments
---------------------

The record set covers three main tectonic environments:

**Active Shallow Crust**
   Earthquakes occurring at depths less than 35 km in tectonically active regions 
   (e.g., Western North America, Mediterranean, Japan).

**Stable Continental Regions**
   Intraplate earthquakes in stable continental interiors with typically lower 
   attenuation rates (e.g., Eastern North America, Northern Europe).

**Subduction Zones**
   Both interface and intraslab earthquakes from subduction environments 
   (e.g., Cascadia, Japan, South America).


Record Selection Criteria
-------------------------

Records were selected following these criteria:

* **Magnitude range**: M\ :sub:`w` 4.5 to 9.0
* **Distance range**: R\ :sub:`jb` 0 to 300 km (Joyner-Boore distance)
* **Minimum PGA**: 0.05g threshold to exclude weak motions
* **Scaling limit**: Maximum scaling factor of 2.5 to preserve spectral shape
* **Site conditions**: V\ :sub:`s30` ranging from 180 to 1500 m/s
* **Uniform distribution**: Records distributed across IM bins to avoid clustering


Intensity Measures
------------------

Multiple intensity measures (IMs) are computed for each record:

.. list-table:: Intensity Measures
   :header-rows: 1
   :widths: 25 75

   * - IM
     - Description
   * - PGA
     - Peak Ground Acceleration [g]
   * - PGV
     - Peak Ground Velocity [m/s]
   * - PGD
     - Peak Ground Displacement [m]
   * - SA(0.3s)
     - Spectral Acceleration at T=0.3s [g]
   * - SA(0.6s)
     - Spectral Acceleration at T=0.6s [g]
   * - SA(1.0s)
     - Spectral Acceleration at T=1.0s [g]
   * - AvgSA
     - Geometric mean of SA over period range [g]
   * - D\ :sub:`5-95`
     - Significant duration (5% to 95% Arias intensity) [s]


Ground-Motion Record Summary
----------------------------

The table below displays the properties of all 700 ground-motion records used in the analysis.

.. raw:: html

   <div id="gm-summary-container">
       <div class="viewer-controls" style="margin-bottom: 15px;">
           <input type="text" id="gm-search" placeholder="Search records..." 
                  style="padding: 8px 12px; border: 1px solid #ddd; border-radius: 4px; width: 300px; margin-right: 10px;">
       </div>
       <div id="gm-summary-table" style="max-height: 500px; overflow: auto; border: 1px solid #e9ecef; border-radius: 6px;">
           <p style="padding: 20px; color: #666;">Loading ground-motion summary...</p>
       </div>
   </div>

   <script>
       document.addEventListener('DOMContentLoaded', async function() {
           const tableContainer = document.getElementById('gm-summary-table');
           const searchInput = document.getElementById('gm-search');

           const paths = [
               '_static/data/in/records/global/GM_summary.csv',
               '_static/data/GM_summary.csv',
               '../_static/data/in/records/global/GM_summary.csv'
           ];
           
           let csvText = null;
           
           for (const path of paths) {
               try {
                   const response = await fetch(path);
                   if (response.ok) {
                       csvText = await response.text();
                       break;
                   }
               } catch (e) {}
           }
           
           if (!csvText) {
               tableContainer.innerHTML = '<div style="padding: 20px; color: #856404; background: #fff3cd;">GM summary not available. Run prepare_data.py first.</div>';
               return;
           }
           
           // Parse CSV properly handling quoted fields
           const lines = csvText.replace(/\r\n/g, '\n').trim().split('\n');
           
           // Parse header - handle quoted headers
           const headerLine = lines[0];
           const headers = [];
           let inQuote = false;
           let field = '';
           for (let i = 0; i < headerLine.length; i++) {
               const c = headerLine[i];
               if (c === '"') {
                   inQuote = !inQuote;
               } else if (c === ',' && !inQuote) {
                   headers.push(field.trim());
                   field = '';
               } else {
                   field += c;
               }
           }
           headers.push(field.trim());
           
           // Parse data rows
           const csvData = [];
           for (let i = 1; i < lines.length; i++) {
               const line = lines[i];
               if (!line.trim()) continue;
               
               const values = [];
               inQuote = false;
               field = '';
               for (let j = 0; j < line.length; j++) {
                   const c = line[j];
                   if (c === '"') {
                       inQuote = !inQuote;
                   } else if (c === ',' && !inQuote) {
                       values.push(field.trim());
                       field = '';
                   } else {
                       field += c;
                   }
               }
               values.push(field.trim());
               
               const row = {};
               headers.forEach((h, idx) => {
                   row[h] = values[idx] || '';
               });
               csvData.push(row);
           }
           
           function renderTable(data) {
               let html = '<table style="width: 100%; border-collapse: collapse; font-size: 11px; white-space: nowrap;">';
               html += '<thead style="position: sticky; top: 0; background: #f8f9fa;">';
               html += '<tr style="border-bottom: 2px solid #dee2e6;">';
               
               headers.forEach(h => {
                   html += '<th style="padding: 8px 6px; text-align: left; font-weight: 600;">' + h + '</th>';
               });
               html += '</tr></thead><tbody>';
               
               data.forEach((row, idx) => {
                   const bgColor = idx % 2 === 0 ? 'white' : '#f8f9fa';
                   html += '<tr style="border-bottom: 1px solid #e9ecef; background: ' + bgColor + ';">';
                   headers.forEach(h => {
                       let val = row[h] || '';
                       const num = parseFloat(val);
                       if (!isNaN(num) && h !== 'Record Name' && h !== 'Record Name in DB' && h !== 'Record RSN') {
                           val = num.toFixed(3);
                       }
                       html += '<td style="padding: 6px;">' + val + '</td>';
                   });
                   html += '</tr>';
               });
               
               html += '</tbody></table>';
               html += '<div style="padding: 10px; background: #f8f9fa; font-size: 11px; color: #666;">Showing ' + data.length + ' of ' + csvData.length + ' records</div>';
               tableContainer.innerHTML = html;
           }
           
           renderTable(csvData);
           
           searchInput.addEventListener('input', () => {
               const query = searchInput.value.toLowerCase();
               const filtered = csvData.filter(row => 
                   Object.values(row).some(v => v.toString().toLowerCase().includes(query))
               );
               renderTable(filtered);
           });
           
       });
   </script>


Record Visualization
--------------------

Select a ground-motion record to view its acceleration time-history and response spectrum.

.. raw:: html

   <div class="viewer-container" id="gm-viewer">
       <div class="viewer-controls">
           <div class="control-group">
               <label for="gm-record-select">Select Record:</label>
               <select id="gm-record-select" class="viewer-select">
                   <option value="">-- Select Record --</option>
               </select>
           </div>
           <div class="control-group">
               <button id="gm-load-btn" class="viewer-btn btn-primary">Load Record</button>
           </div>
       </div>
       <div style="display: grid; grid-template-columns: 1fr 1fr; gap: 20px;">
           <div class="viewer-plot" id="gm-acc-plot" style="height: 350px;"></div>
           <div class="viewer-plot" id="gm-spectrum-plot" style="height: 350px;"></div>
       </div>
   </div>

   <script>
       document.addEventListener('DOMContentLoaded', async function() {
           const recordSelect = document.getElementById('gm-record-select');
           const loadBtn = document.getElementById('gm-load-btn');
           
           // Load GM summary to populate dropdown
           const paths = [
               '_static/data/in/records/global/GM_summary.csv',
               '_static/data/GM_summary.csv'
           ];
           
           let gmData = [];
           
           for (const path of paths) {
               try {
                   const response = await fetch(path);
                   if (response.ok) {
                       const text = await response.text();
                       const lines = text.replace(/\r\n/g, '\n').trim().split('\n');
                       const headers = lines[0].split(',').map(h => h.trim().replace(/"/g, ''));
                       
                       for (let i = 1; i < lines.length; i++) {
                           const values = lines[i].match(/(".*?"|[^",]+)(?=\s*,|\s*$)/g) || [];
                           const row = {};
                           headers.forEach((h, idx) => {
                               row[h] = values[idx]?.trim().replace(/"/g, '') || '';
                           });
                           gmData.push(row);
                       }
                       break;
                   }
               } catch (e) {}
           }
           
           // Populate dropdown
           gmData.forEach((record, idx) => {
               const opt = document.createElement('option');
               opt.value = idx;
               const name = record['Record Name'] || record['Record Name in DB'] || `Record ${idx}`;
               const mag = record['Magnitude, Mw'] ? ` (M${parseFloat(record['Magnitude, Mw']).toFixed(1)})` : '';
               opt.textContent = name + mag;
               recordSelect.appendChild(opt);
           });
           
           loadBtn.addEventListener('click', async function() {
               const idx = recordSelect.value;
               if (idx === '') {
                   alert('Please select a record');
                   return;
               }
               
               const record = gmData[idx];
               // Prefer gm_file (new format: acc_N.csv); fall back to Record Name in DB
               // mapping gmr_N.csv -> acc_N.csv for the older summary format.
               const rawName = record['gm_file'] || record['Record Name in DB'] || `acc_${idx}.csv`;
               const accFileName = rawName.replace(/^gmr_/, 'acc_');
               const baseName = accFileName.replace('.csv', '');

               // Load acceleration time-history
               const accPaths = [
                   `_static/data/in/records/global/acc/${accFileName}`,
                   `_static/data/in/records/global/acc/${rawName}`
               ];
               
               let accData = null;
               for (const path of accPaths) {
                   try {
                       const response = await fetch(path);
                       if (response.ok) {
                           const text = await response.text();
                           const lines = text.replace(/\r\n/g, '\n').trim().split('\n');
                           accData = { dt: [], acc: [] };
                           
                           // Check if first line is header
                           const firstLine = lines[0].split(',');
                           const startIdx = isNaN(parseFloat(firstLine[0])) ? 1 : 0;
                           
                           let time = 0;
                           for (let i = startIdx; i < lines.length; i++) {
                               const vals = lines[i].split(',');
                               const dt = parseFloat(vals[0]);
                               const acc = parseFloat(vals[1]);
                               if (!isNaN(dt) && !isNaN(acc)) {
                                   time += dt;
                                   accData.dt.push(time);
                                   accData.acc.push(acc);
                               }
                           }
                           break;
                       }
                   } catch (e) {}
               }
               
               // Plot acceleration
               if (accData && accData.dt.length > 0) {
                   Plotly.newPlot('gm-acc-plot', [{
                       x: accData.dt,
                       y: accData.acc,
                       mode: 'lines',
                       line: { color: '#2980b9', width: 0.8 },
                       name: 'Acceleration'
                   }], {
                       title: { text: 'Acceleration Time-History', x: 0.5 },
                       xaxis: { title: 'Time [s]', gridcolor: '#ecf0f1' },
                       yaxis: { title: 'Acceleration [g]', gridcolor: '#ecf0f1' },
                       paper_bgcolor: '#fcfcfc', plot_bgcolor: 'white',
                       margin: { t: 50, b: 50, l: 60, r: 30 },
                       showlegend: false
                   }, { responsive: true, displaylogo: false });
               } else {
                   document.getElementById('gm-acc-plot').innerHTML = 
                       '<div style="padding: 20px; color: #666;">Acceleration data not available</div>';
               }
               
               // Load spectrum
               const recIdx = baseName.replace(/^(acc_|gmr_)/, '');
               const specPaths = [
                   `_static/data/in/records/global/spectra/spectrum_${recIdx}.csv`,
                   `_static/data/in/records/global/spectra/spec_${recIdx}.csv`
               ];
               
               let specData = null;
               for (const path of specPaths) {
                   try {
                       const response = await fetch(path);
                       if (response.ok) {
                           const text = await response.text();
                           const lines = text.replace(/\r\n/g, '\n').trim().split('\n');
                           specData = { prd: [], sa: [], sv: [], sd: [] };
                           
                           const startIdx = isNaN(parseFloat(lines[0].split(',')[0])) ? 1 : 0;
                           
                           for (let i = startIdx; i < lines.length; i++) {
                               const vals = lines[i].split(',');
                               if (vals.length >= 4) {
                                   specData.prd.push(parseFloat(vals[0]));
                                   specData.sd.push(parseFloat(vals[1]));
                                   specData.sv.push(parseFloat(vals[2]));
                                   specData.sa.push(parseFloat(vals[3]));
                               }
                           }
                           break;
                       }
                   } catch (e) {}
               }
               
               // Plot spectrum - LINEAR x-axis from 0 to 4 seconds
               if (specData && specData.prd.length > 0) {
                   Plotly.newPlot('gm-spectrum-plot', [{
                       x: specData.prd,
                       y: specData.sa,
                       mode: 'lines',
                       line: { color: '#e74c3c', width: 2 },
                       name: 'SA'
                   }], {
                       title: { text: 'Response Spectrum (5% damping)', x: 0.5 },
                       xaxis: { title: 'Period [s]', range: [0, 4], gridcolor: '#ecf0f1' },
                       yaxis: { title: 'Spectral Acceleration [g]', gridcolor: '#ecf0f1' },
                       paper_bgcolor: '#fcfcfc', plot_bgcolor: 'white',
                       margin: { t: 50, b: 50, l: 60, r: 30 },
                       showlegend: false
                   }, { responsive: true, displaylogo: false });
               } else {
                   document.getElementById('gm-spectrum-plot').innerHTML = 
                       '<div style="padding: 20px; color: #666;">Spectrum data not available</div>';
               }
           });
       });
   </script>


References
----------

* Ancheta T.D. et al. (2014). NGA-West2 Database. Earthquake Spectra.

* Goulet C.A. et al. (2021). NGA-East Ground-Motion Models for the U.S. Geological Survey 
  National Seismic Hazard Maps. Earthquake Spectra.

* Parker G.A. et al. (2020). NGA-Subduction Global Ground-Motion Models with Regional 
  Adjustment Factors. Earthquake Spectra.

* Luzi L. et al. (2020). Engineering Strong Motion Database (ESM). European facilities 
  for earthquake hazard and risk.

* Aoi S. et al. (2020). MOWLAS: NIED observation network for earthquake seismology and 
  engineering. Earth, Planets and Space.